Method and system for establishing microlocation zones

ABSTRACT

A method and system of creating microlocation zones by defining virtual boundaries using a system of one or more transmitters and receivers with one or more spatially-correlated antennas.

TECHNICAL FIELD

The present disclosure is directed to a system and method of creatingmicrolocation zones by defining virtual boundaries using a system of oneor more transmitters and one or more receivers with one or morespatially-correlated antennas.

BACKGROUND

Significant efforts have been made toward enabling the utilization ofsmartphones as keys to access or command the operation of an equipmentdevice, such as a door or a vehicle. Conventional systems may rely onsignal strength of communications to determine relative distance and/orposition between a transmitter and a receiver. For instance, manyconventional systems measure signal strength with a directional antennato determine the relative distance and/or position between a transmitterand a receiver. This conventional arrangement has several limitations,but the principal limitation is location accuracy. Several factors canaffect location accuracy. Examples of such factors include physicalboundaries, external objects, and moving objects, and moving aspects ofthe equipment device. Conventional systems may fail to achieve ormaintain location accuracy in view of these or other factors.

SUMMARY OF THE DESCRIPTION

The present disclosure is directed to a method and system of creatingmicrolocation zones by defining virtual boundaries using a system of oneor more transmitters and one or more receivers with one or morespatially-correlated antennas.

In one embodiment, a system is provided for establishing locationinformation with respect to a portable device and an object. The systemmay include a master device and a plurality of antennas. The masterdevice may be disposed in a fixed position relative to the object, andmay be capable of communicating with at least one of the portable deviceand one or more sensor devices. Each of the plurality of antennas may beconfigured to receive wireless communications, where a signalcharacteristic of the wireless communications is detected via an antennasignal output from each of said plurality of antennas.

In one embodiment, the signal characteristic is a measurement (or aderivation of a measurement, such as a computed distance or time offlight) of the antenna signal output. A plurality of time-spacedmeasurements of the signal characteristic may be conducted to form ameasured characteristic signal. The measurements may be conducted withrespect to wireless communications that occur at two or more of aplurality of different frequencies. For instance, the portable devicemay transmit communications at a frequency within a set of differentfrequencies. The frequency of transmission may vary over time among theset of different frequencies. The measurements of the antenna signaloutput may be correlated in time and frequency with measurements fromanother antenna signal output.

In one embodiment, the measurements of the antenna signal output may besmoothed according to a smoothing function with the smoothed outputforming the basis for a location determination with respect to theportable device.

In one embodiment, one or more a combined signals may be determined as afunction of at least two characteristic signals from a single antennaand/or at least two characteristic signals from two or more separateantennas. For instance, the function may be a difference function andthe combined signal may be a differential signal with respect to the atleast two characteristic signals. The combined signal may be correlatedin time with the at least two characteristic signals, and the at leasttwo characteristic signals may be correlated in time and frequency, asnoted above. A location of the portable device may be determinedrelative to the object based on the combined signal. The function maymitigate fading and other environmental effects present in the at leasttwo of said detected signal characteristics. The function applied to atleast two characteristic signals may be different from another functionapplied to at least two characteristic signals. In one embodiment, acombined signal may be determined as a function of at least two aspectsof a single characteristic signal that occur at different times.

In one embodiment, the master device is configured to determine thecombined signal and the location of the portable device based on thecombined signal. In one embodiment, the at least one sensor device maycommunicate one or more signal characteristics of the combined signal tothe master device via a communication channel separate from acommunication channel used for reception of the wireless communications.

In one embodiment, the characteristic signals are correlated in time andfrequency with respect to wireless communications received by theplurality of antennas. In one embodiment, a first antenna and a secondantenna of said plurality of antennas are spatially correlated such thatthe first and second antennas are separated by a ground plane or otherobject that may divide the RF path between two or more antennas (e.g.,an attenuator or a reflector).

In one embodiment, the plurality of antennas are arranged and the signaloutput from the plurality of antennas is analyzed to define a pluralityof zones that define at least one virtual boundary. In one embodiment,the at least two of the measurements are conducted with respect todifferent communication frequencies.

In one embodiment, one or more signal characteristics of the wirelesscommunications are detected via antenna signal output from saidplurality of antennas. The one or more signal characteristics mayinclude at least one of a time of flight characteristic, a signalstrength characteristic, and an angle of arrival/departurecharacteristic, where a location of the portable device is determinedrelative to the object based on the one or more signal characteristicsof the wireless communications. In one embodiment, the one or moresignal characteristics of the wireless communications may include aplurality of one type of signal characteristic (e.g., two signalstrength readings, two angle of arrival measurements).

In one embodiment, the plurality of antennas may include first andsecond antennas arranged to define a first virtual boundary betweenfirst and second zones, where a position of the portable device relativeto the first virtual boundary is determined based on a differencebetween a first signal characteristic determined from antenna signaloutput from the first antenna and a second signal characteristicdetermined from antenna signal output from the second antenna. Theplurality of antennas may include third and fourth antennas arranged todefine a second virtual boundary between third and fourth zones, where aposition of the portable device relative to the second virtual boundaryis determined based on a difference between a third signalcharacteristic determined from antenna signal output from the thirdantenna and a fourth signal characteristic determined from antennasignal output from the fourth antenna. In one embodiment, a virtualboundary may be defined between a) a zone based on an arrangement of thefirst and second antennas and b) a zone corresponding to the thirdantenna, and likewise between a) a zone based on the arrangement of thefirst and second antennas and b) the fourth antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a representative view of a system in accordance with oneembodiment.

FIG. 2 shows a representative view of an electronic component inaccordance with one embodiment.

FIG. 3 shows system in accordance with one embodiment.

FIG. 4 depicts directional antenna radiation pattern features inaccordance with one embodiment.

FIG. 5 shows an omni directional antenna with one zone in accordancewith one embodiment.

FIG. 6 depicts an omni directional antenna with two zones in accordancewith one embodiment.

FIG. 7 shows one directional antenna creating one zone, with deviceoutside of the zone of reception in accordance with one embodiment.

FIG. 8 shows one directional antenna creating one zone, with deviceinside of zone of reception in accordance with one embodiment.

FIG. 9 depicts two back-to-back directional antennas producing two zonesand one boundary in accordance with one embodiment.

FIG. 10 shows device located on “left” side of virtual boundary, in ZoneA in accordance with one embodiment.

FIG. 11 shows device located on “right” side of virtual boundary, inZone B in accordance with one embodiment.

FIG. 12 depicts three back-to-back directional antennas, producing threezones and three boundaries in accordance with one embodiment.

FIG. 13 shows four back-to-back directional antennas with antennaboresight in opposite orientation in accordance with one embodiment.

FIG. 14 shows four back-to-back directional antennas with two exampledevice locations in accordance with one embodiment.

FIG. 15 depicts six back-to-back directional antennas with six zones(virtual boundaries not shown) in accordance with one embodiment.

FIG. 16 shows compound zones created from overlapping zones inaccordance with one embodiment.

FIG. 17 shows zones created by adjacent directional antennas inaccordance with one embodiment.

FIG. 18 shows a zone or compound zone on both sides of a door inaccordance with one embodiment.

FIG. 19 depicts vehicle interior with four zones in accordance with oneembodiment.

FIG. 20 includes a vehicle showing inside/outside zones in accordancewith one embodiment.

FIG. 21 shows a three antenna vehicle microlocation system using RSSI inaccordance with one embodiment.

FIG. 22 shows a seven antenna vehicle microlocation system using RSSI inaccordance with one embodiment.

FIG. 23 depicts an eleven antenna vehicle microlocation system usingRSSI in accordance with one embodiment.

FIG. 24 shows antennas on movable parts of equipment using RSSI inaccordance with one embodiment.

FIG. 25 shows antennas on movable parts of equipment using RSSI inaccordance with one embodiment.

FIG. 26 shows antennas on movable parts of equipment using RSSI inaccordance with one embodiment.

FIG. 27 shows antennas on movable parts of equipment using RSSI inaccordance with one embodiment.

FIG. 28 depicts antennas on movable parts of equipment using angle ofarrival in accordance with one embodiment.

FIG. 29 depicts antennas on movable parts of equipment using angle ofarrival in accordance with one embodiment.

FIG. 30 depicts antennas on movable parts of equipment using angle ofarrival in accordance with one embodiment.

FIG. 31 depicts antennas on movable parts of equipment using angle ofarrival in accordance with one embodiment.

FIG. 32 shows alternate exterior antenna configurations using angle ofarrival (4 antennas) in accordance with one embodiment.

FIG. 33 shows alternate exterior antenna configurations using angle ofarrival (4 antennas) in accordance with one embodiment.

FIG. 34 shows alternate exterior antenna configurations using angle ofarrival (2, 5, 6, and 8 antennas) in accordance with one embodiment.

FIG. 35 shows alternate exterior antenna configurations using angle ofarrival (2, 5, 6, and 8 antennas) in accordance with one embodiment.

FIG. 36 shows alternate exterior antenna configurations using angle ofarrival (2, 5, 6, and 8 antennas) in accordance with one embodiment.

FIG. 37 shows alternate exterior antenna configurations using angle ofarrival (2, 5, 6, and 8 antennas) in accordance with one embodiment.

FIG. 38 shows alternate interior antenna configurations using angle ofarrival (1, 2, and 4 antennas) in accordance with one embodiment.

FIG. 39 shows alternate interior antenna configurations using angle ofarrival (1, 2, and 4 antennas) in accordance with one embodiment.

FIG. 40 shows alternate interior antenna configurations using angle ofarrival (1, 2, and 4 antennas) in accordance with one embodiment.

FIG. 41 shows alternate interior antenna configurations using angle ofarrival (1, 2, and 4 antennas) in accordance with one embodiment.

FIG. 42 shows alternate interior antenna configurations using angle ofarrival (1, 2, and 4 antennas) in accordance with one embodiment.

FIG. 43 shows alternate interior antenna configurations using angle ofarrival (1, 2, and 4 antennas) in accordance with one embodiment.

FIG. 44 shows fading in a small region in accordance with oneembodiment.

FIG. 45 depicts Rayleigh probability functions in accordance with oneembodiment.

FIG. 46 illustrates a two-antenna configuration in accordance with oneembodiment.

FIG. 47 shows a pattern of the antenna configuration in FIG. 46 inaccordance with one embodiment.

FIG. 48 shows a twelve antenna vehicle microlocation system using angleof arrival in accordance with one embodiment.

FIG. 49 depicts a twenty-three antenna vehicle microlocation systemusing angle of arrival and RSSI in accordance with one embodiment.

FIG. 50 shows a nineteen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 51 shows a seventeen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 52 depicts a fifteen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 53 shows an alternate fifteen antenna vehicle microlocation systemusing angle of arrival and RSSI in accordance with one embodiment.

FIG. 54 depicts a fifteen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 55 shows a thirteen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 56 shows an eleven antenna vehicle microlocation system using angleof arrival and RSSI in accordance with one embodiment.

FIG. 57 depicts an eighteen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 58 shows a eighteen antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 59 depicts a twelve antenna vehicle microlocation system usingangle of arrival and RSSI in accordance with one embodiment.

FIG. 60 shows a thirteen combined antenna vehicle microlocation systemusing angle of arrival and RSSI in accordance with one embodiment.

FIG. 61 shows a thirteen combined antenna vehicle microlocation systemusing angle of arrival and RSSI—alternate placement in accordance withone embodiment.

FIG. 62 depicts a fifteen combined antenna vehicle microlocation systemusing angle of arrival and RSSI in accordance with one embodiment.

FIG. 63 depicts an eleven combined antenna vehicle microlocation systemusing angle of arrival and RSSI—centers in accordance with oneembodiment.

FIG. 64 depicts an eleven combined antenna vehicle microlocation systemusing angle of arrival and RSSI in accordance with one embodiment.

FIG. 65 depicts a seven combined antenna vehicle microlocation systemusing angle of arrival and RSSI in accordance with one embodiment.

FIG. 66 depicts multiangulation and triangulation using angle of arrivaland RSSI in accordance with one embodiment.

FIG. 67 shows alternate exterior antenna configurations using angle ofarrival (4 antennas) in accordance with one embodiment.

Before the embodiments of the invention are explained in detail, it isto be understood that the invention is not limited to the details ofoperation or to the details of construction and the arrangement of thecomponents set forth in the following description or illustrated in thedrawings. The invention may be implemented in various other embodimentsand of being practiced or being carried out in alternative ways notexpressly disclosed herein. Also, it is to be understood that thephraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use of“including” and “comprising” and variations thereof is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items and equivalents thereof. Further, enumeration may beused in the description of various embodiments. Unless otherwiseexpressly stated, the use of enumeration should not be construed aslimiting the invention to any specific order or number of components.Nor should the use of enumeration be construed as excluding from thescope of the invention any additional steps or components that might becombined with or into the enumerated steps or components.

DESCRIPTION A. System Overview

A.1 System Architecture

The present disclosure is directed to a method and system of creatingmicrolocation zones by defining virtual boundaries using a system of oneor more transmitters and one or more receivers with one or morespatially-correlated antennas. Such a system is designated 100 in theillustrated embodiment of FIG. 1.

The present disclosure addresses several failings of conventionalsystems, and provides system component (sensor) designs, that may usesignal processing methods and techniques. The system and method forcombining sensors is also described, such that they may be assembled andprocessed using the described methods to produce variable, user-definedconfigurations in a variety of applications/embodiments, including, butnot limited to, microlocation systems that operate using Bluetooth LowEnergy (BLE).

The system and method may use directional and/or omnidirectionalantennas to determine relative distance and/or position using receivedsignal strength indicators (RSSIs) (e.g., possibly employingtrilateration, fingerprinting, etc.), time-of-flight measurements,angle-of-arrival/departure (AoA, e.g., possibly employing triangulation,etc.), or any number of other established distance measuring and/orpositioning techniques.

One embodiment according to the present disclosure uses a differentialtechnique based upon measured RSSIs to determine in which zone a deviceis located, but the system is not limited to using RSSI nor is the useof any one or more particular positioning techniques to create ordetermine microlocation zones precluded (e.g., the zone of a device maybe determined using the differential of the most likely AoA, earliestarrival time, triangulated position, trilaterated position, and so on,instead of, or in addition to, measured RSSI).

While the embodiments described herein describe the use of radiofrequency signaling, other types of signaling may be used, contingentupon the suitability and limitations present using those other types ofsignaling. For example, it may be possible to use light or sound as analternative to radio frequency signals.

In one embodiment, an antenna is provided similar to the one shown inFIG. 4 and designated 312. The illustrated embodiment of FIG. 4 shows anantenna 312 that is directional, but the present disclosure is not solimited—the antenna 312 may be configured differently, includingconfigured as an omnidirectional antenna. The antenna configuration ofthe directional antenna in one embodiment may be such that thecharacteristic radiation pattern is sufficient for the application ofone or more embodiments described herein. In one embodiment, the antenna312 is configured to include an emphasized main lobe 314 and minimized(or reduced size) side and back lobes 316, 318. Note that in theillustrations provided, the radiation patterns shown are meant to showtypical patterns, but are not restricted to the shape or shapes shown;the actual radiation pattern may vary and may be impacted by theconstruction of the sensor (including the antenna) and the materialssurrounding the sensor (to the possible advantage or detriment of thesystem). Subsequent illustrated embodiments may use a simplified antennaradiation pattern to illustrate the radiation pattern (ellipse orsimilar).

A.2 Antenna Reciprocity

In the following method and system described, the directional antennamay be connected to a transmitter or receiver. For instance, the antenna312 may be incorporated into or coupled to a sensor 310 (also describedas a remote device). As another example, the antenna 312 may beincorporated into or coupled to one or more of the following: systemcontrol module 120, equipment components 140, and a portable device 110.Any one of these example devices may be configured to transmit orreceive, or both, using the antenna 312. There are a variety of antennaembodiments described herein, some of which include more than oneantenna 312. In this way, an antenna 312 may itself be comprised of morethan one type of antenna 312 in accordance with one or more embodimentsof the antenna 312 described herein. For instance, an antenna 312 mayinclude first and second antennas 312 arranged to focus on first andsecond zones 400. Any of the embodiments described herein may use anyone or more of the antennas 312 described herein.

A.3 Definition of Sensor

For the subsequent explanations, the part of the transmitter/receiversystem connected to the antenna will be referred to as the sensor 310.

A.4 Definition of Device

For the subsequent explanations, the part of the transmitter/receiversystem opposite from the sensor will be referred to as the device 110.The device 110 may or not be portable, but in several of the embodimentsshown, it is portable. This portability may be associated with thedevice 110 being carried by a human. In one embodiment, the device 110is the object whose position is of interest relative to sensors 310;however, the reverse may also be true, wherein the device 110 isconfigured to determine the location of sensors 310 relative to itself.

Described herein is a system 100 in one embodiment in which sensors 310may be used in conjunction with each other to createapplication-specific microlocation systems; that is, sensors 310 may beused in conjunction with each other to create microlocation zones thatmay be used to determine the relative position of a device 110. One ormore aspects of the system 100 may be implemented in conjunction withone or more aspects of the microlocation systems described in U.S.Nonprovisional application Ser. No. 14/620,959 to J. Michael Ellis etal., filed Feb. 12, 2015, and entitled SYSTEM AND METHOD FORCOMMUNICATING WITH A VEHICLE, U.S. Provisional Appl. No. 62/323,262 toRaymond Michael Stitt, filed Apr. 15, 2016, and entitled SYSTEM ANDMETHOD FOR ESTABLISHING REAL-TIME LOCATION—the disclosures of which areincorporated herein by reference in their entirety. The system 100 mayinclude sensors 310 equipped with the subsequently described antennaconfigurations 312.

A.5 System Components

A system according to one embodiment is shown in FIG. 1 and generallydesignated 100. The system 100 may include one or more of the followingsystem components: a) one or more users 10 (e.g., people); b) one ormore devices 110, such as portable devices (e.g., smartphones, cards orfobs, or a combination thereof) and/or fixed devices (e.g.,computers/servers, or wall-mounted panels/displays, or a combinationthereof; c) one or more system control modules (SCM) 120, also describedas hardware; d) one or more sensors 310 (which may be optional); and e)one or more equipment components 140, which may be configured forcontrolling equipment operations, activating services thereon, relayinginformation to another aspect of the system 100, or retrievinginformation from another aspect of the system 100, or a combinationthereof.

The system 100 may allow the one or more users 10 to interact with oraccess the equipment 140 using the device 110. The device 110 maycommunicate with the equipment 140 (such as a vehicle, a lock, or atable) by communicating with the SCM 120. The SCM 120 in one embodimentmay authenticate the device 110, provide or receive configuration data,authorize actions (e.g., to connect or to send and/or receive a request,a command, an update, or a response, or a combination thereof), orcommunicate with the equipment component 140 to achieve a desiredaction, or a combination thereof. The device 110 may communicate with acloud (not shown) to obtain, change, or distribute, or a combinationthereof, authorizations (described herein), and other configurationdata, amongst relevant devices and users. An example of such a system isshown and described in U.S. patent application Ser. No. 15/796,180 toSmith et al., filed Oct. 27, 2017, entitled SYSTEM AND METHOD FORAUTHENTICATING AND AUTHORIZING DEVICES—the disclosure of which is herebyincorporated by reference in its entirety.

A.5.a Communications and Interaction Overview

The communication links between the one or more system componentsdepicted in the illustrated embodiment of FIG. 1 may be wireless orwired, or both. One system component, such as the device 110, may belocal or remote relative to another system component, such the SCM 120.The system 100 may include any number of each system component,including embodiments in which the number is zero such as where noequipment is present.

In one embodiment, the roles of a system component in the system 100 arenot necessarily fixed as one type of component. For instance, a systemcomponent may change roles dynamically during operation, or a systemcomponent may take on the role of two or more components of the system100. For instance, the SCM 120 may be the equipment component 140 foranother SCM 120. In a more specific form of this example, the SCM 120may be the equipment component 140 communicating with the other SCM 120.For purposes of disclosure, the remaining discussion focuses upon asystem 100 wherein the one or more equipment components 140exist—although it should be understood that one or more of these systemcomponents may be absent. Optionally, the system 100 may be configuredto communicate with another system, such as a cloud system of devices.

A.5.b Component Overview

The system 100 in the illustrated embodiment may include one or moresystem components as outlined herein. A system component may be a useror an electronic system component, which may be the device 110, the SCM120, the equipment component 140, or the cloud, or a combinationthereof. The electronic system component, as discussed herein, may beconfigured to operate as any one or more of these devices. In thissense, in one embodiment, there may be several aspects or featurescommon among the device 110, the SCM 120, the equipment component 140,and the cloud. For purposes of disclosure, these features are describedin connection with the electronic component depicted in FIG. 2 andgenerally designated 200.

The electronic system component 200 (e.g., all system components, exceptusers) may include one or more processors 210 that execute one or moreapplications 232 (software and/or includes firmware), one or more memoryunits 212 (e.g., RAM and/or ROM), and one or more communications units214, amongst other electronic hardware. The electronic system component200 may or may not have an operating system 230 that controls access tolower-level devices/electronics via a communication unit 214. Theelectronic system component 200 may or may not have hardware-basedcryptography units 222—in their absence, cryptographic functions may beperformed in software. The electronic system component 200 may or maynot have (or have access to) secure memory units 220 (e.g., a secureelement or a hardware security module (HSM)). Optional components andcommunication paths are shown in phantom lines in the illustratedembodiment.

The system 100 in the illustrated embodiment is not dependent upon thepresence of a secure memory unit 220 in any component. In the optionalabsence of a secure memory unit 220, data that may be stored in thesecure memory unit 220 (e.g., private and/or secret keys) may beencrypted at rest (when possible). Both software-based andhardware-based mitigations may be utilized to substantially preventaccess to such data, as well as substantially prevent or detect, orboth, overall system component compromise. Examples of such mitigationfeatures include implementing physical obstructions or shields,disabling JTAG and other ports, hardening software interfaces toeliminate attack vectors, using trusted execution environments (e.g.,hardware or software, or both), and detecting operating system rootaccess or compromise.

For purposes of disclosure, being secure is generally considered beingconfidential (encrypted), authenticated, and integrity-verified. Itshould be understood, however, that the present disclosure is not solimited, and that the term “secure” may be a subset of these aspects ormay include additional aspects related to data security.

The communication interface 214 may be any type of communication link,including any of the types of communication links describe herein,including wired or wireless. The communication interface 214 mayfacilitate external or internal, or both, communications. For instance,the communication interface 214 may be coupled to or incorporate anantenna 312.

As another example, the communication interface 214 may provide awireless communication link with another system electronic device 200 inthe form of the device 110, such as wireless communications according tothe Bluetooth LE standard, or the cloud 130 via WiFi Ethernetcommunication link. In another example, the communication interface 214may be configured to communicate with the equipment component 140 (e.g.,a vehicle component) via a wired link such as a CAN-based wired networkthat facilitates communication between a plurality of devices. Thecommunication interface 214 in one embodiment may include a displayand/or input interface for communicating information to and/or receivinginformation from the user 10.

In one embodiment, shown in FIG. 2, the electronic system component 200may be configured to communicate with one or more auxiliary devices 300other than another electronic system component 200 or a user. Theauxiliary device 300 may be configured differently from the electronicsystem component 200—e.g., the auxiliary device 300 may not include aprocessor 210, and instead, may include at least one direct connectionand/or a communication interface for transmission or receipt, or both,of information with the electronic system component 200. For instance,the auxiliary device 300 may be a solenoid that accepts an input fromthe electronic system component 200, or the auxiliary device 300 may bea sensor (e.g., a proximity sensor) that provides analog and/or digitalfeedback to the electronic system component 200.

A.5.c Micro-Location

The system 100 in the illustrated embodiment may be configured todetermine location information in real-time with respect to the device110. In the illustrated embodiment of FIG. 1, the user 10 may carry thedevice 110 (e.g., a smartphone). The system 100 may facilitate locatingthe device 110 with respect to the equipment 140 (e.g., a vehicle) inreal-time with sufficient precision to determine whether the user islocated at a position at which access to the equipment or permission foran equipment command should be granted.

For instance, in the realm of vehicles where the equipment 140 is avehicle, the system 100 may facilitate determining whether the device110 is outside the vehicle but in close proximity, such as within 5feet, 3 feet, or 2 feet or less, to the driver-side door. Thisdetermination may form the basis for identifying whether the system 100should unlock the vehicle. On the other hand, if the system 100determines the device 110 is outside the vehicle and not in closeproximity to the driver-side door (e.g., outside the range of 2 feet, 3feet, or 5 feet), the system 100 may determine to lock the driver-sidedoor. As another example, if the system 100 determines the device 110 isin close proximity to the driver-side seat but not in proximity to thepassenger seat or the rear seat, the system 100 may determine to enablemobilization of the vehicle. Conversely, if the device 110 is determinedto be outside close proximity to the driver-side seat, the system 100may determine to immobilize or maintain immobilization of the vehicle.

The vehicle in this context may also include other types of equipment140, such as one or more sensors 310 described in connection with theillustrated embodiment of FIG. 3. The one or more sensors 310 may beconstructed in a manner similar to an embodiment described in connectionwith the electronic system component 200.

Micro-location of the equipment 140 may be determined in a variety ofways, such as using information obtained from a global positioningsystem, one or more signal characteristics of communications from adevice 110, and one or more sensors (e.g., a proximity sensor, a limitswitch, or a visual sensor), or a combination thereof. An example ofmicrolocation techniques for which the system 100 can be configured aredisclosed in U.S. Nonprovisional patent application Ser. No. 15/488,136to Raymond Michael Stitt et al., entitled SYSTEM AND METHOD FORESTABLISHING REAL-TIME LOCATION, filed Apr. 14, 2017—the disclosure ofwhich is hereby incorporated by reference in its entirety.

In one embodiment, in the illustrated embodiment of FIG. 3, the SCM 120and a plurality of sensors 310 may be disposed on or in a fixed positionrelative to the equipment component 140. Example use cases of theequipment component 140 include the vehicle identified in the priorexample, or a building for which access is controlled by the equipmentcomponent 140. The sensors 310 in the illustrated embodiment may includeone or more antennas 312 as described herein. The arrangement orposition of the sensors 310 may be in accordance with one or moreembodiments described herein. Signal processing of the SCM 120 may be inaccordance with one or more embodiments described herein.

The device 110 may communicate wirelessly (e.g., via Bluetooth LE) withthe SCM 120 via a communication link. The plurality of sensors 310 maybe configured to sniff the communications between the device 110 and theSCM 120 to determine one or more signal characteristics of thecommunications, such as signal strength. The determined signalcharacteristics may be communicated or analyzed and then communicated tothe SCM 120 via a communication link separate from the communicationlink between the device 110 and the SCM 120. Additionally, oralternatively, the device 110 may establish a direct communication linkwith one or more of the sensors 310, and the one or more signalcharacteristics may be determined based on this direct communicationlink.

As an example, as shown in the illustrated embodiment, the propagationwaves of communications from the device 110 to the SCM 120 are shown anddesignated 302, 304, 306. The greater the distance from the device 110(the source), the lesser the strength of the wireless communications.The strength of the communications about the propagation wave 306 isless than the strength of the propagation wave 302. Further, in the caseof a communication being transmitted at time t0, the travel time(tp1-t0) for the communication at the propagation wave 302 is less thanthe travel time (tp3-t0) for the communication at propagation wave 306.As a result, if a sensor 310 receives the communication at thepropagation wave 302, the time stamp for arrival of the communicationmay be earlier than if the communication were received at thepropagation wave 306.

As described herein, one or more signal characteristics, such as signalstrength and time of arrival, may be analyzed to determine locationinformation about the device 110 relative to the SCM 120. For instance,time difference of arrival among the sensors 310 and the SCM 120 may beprocessed to determine a relative position of the device 110. Thepositions of the one or more sensors 310 relative to the SCM 120 may beknown so that the relative position of the device 110 can be translatedto an absolute position with respect to the sensors 310 and the SCM 120.Additional or alternative examples of signal characteristics may beobtained to facilitate determining position according to one or morealgorithms, including a distance function, trilateration function, atriangulation function, a multilateration function, a fingerprintingfunction, a differential function, a time of flight function, a time ofarrival function, a time difference of arrival function, an angle ofarrival function, an angle of departure function, a geometric function,etc., or any combination thereof.

It should be noted that for purposes of illustration, the propagationwaves 302, 304, 306 are depicted as uniformly circular—however, thepropagation waves may vary in shape depending on other factors such asinterference or use of a directional antenna.

In one embodiment, information relating to the communications betweenthe device 110 and the SCM 120 may be provided to the plurality ofsensors 310. For instance, connection parameters relating to a BluetoothLE channel may be provided to the sensors 310 so that the plurality ofsensors 310 can monitor the communications. For instance, thecommunication channel may vary one or more parameters duringcommunications, such as the frequency of transmissions from packet topacket or among bits transmitted in the packet. These one or morevariable parameters may be communicated to the sensors 310 to enablereceipt of packets or communications.

B. One or More Example Antenna Configurations Adopted in One or MoreEmbodiments

B.1 Omni-Directional Antenna

An antenna 312 in accordance with one embodiment is shown in theillustrated embodiment of FIG. 5. The antenna 312 in the illustratedembodiment is a single omni-directional antenna configured to produce aroughly circular zone of reception, also described as a zone 400. Adevice 110 location can be in one of two states, either in the zone 400,or not. An example of such an antenna configuration is shown in theillustrated embodiment of FIG. 3. The zone radius or radius of the zone400 may be defined either by a threshold (RSSI, computed distance fromorigin, etc.) or it may be defined by the receive range of the antenna312.

Additionally, multiple thresholds may be defined, such that there aremultiple zones 400 within the receive range of the antenna 312. Anexample of such an antenna configuration is shown in FIG. 6, andincludes an outside zone 404 and an inside zone 402.

B.2 Directional Antenna with One Zone

A single directional antenna 312 is shown in the illustrated embodimentsof FIGS. 7 and 8. The directional antenna 312 in the illustratedembodiment is configured to produce one zone 400 of reception. A devicelocation can be in one of two states, either in the zone 400, or not.The zone field 400 (or zone area 400) may be defined either by athreshold (RSSI, computed distance from origin, etc.) or it may bedefined by the receive range of the antenna 312. Additionally, multiplethresholds may be defined, such that there are multiple zones 400 withinthe receive range of the antenna 312.

B.3 One Directional Antenna Pair with Two Zones and One Virtual Boundary

One embodiment of an antenna 312 in a paired configuration with onevirtual boundary 410 is shown in FIGS. 9-11. In the illustratedembodiments, two spatially correlated directional antennas, designated312A, 312B, (i.e., a pair), whose antenna boresights are orientedopposite to each other, yield two zones 400A, 400B, as well as onevirtual boundary 410A-B between the two zones 400A, 400B. Alternatively,one embodiment of the antenna 312 may be configured with a first antenna312 and a second antenna 312 with boresights not oriented opposite, butseparated by a ground plane, or other object that may divide the RF pathbetween two or more antennas (e.g., an attenuator or a reflector), toyield two zones 400. The ground plane or other object that divides theRF path (e.g., an attenuator or a reflector) may yield a similar effectas the oppositely oriented boresights.

In one embodiment, such an antenna 312 pair, each antenna 312 may becoupled to a sensor 310 (e.g., two sensors 310 each with one antenna312), wherein each sensor 310 may communicate measurements substantiallysimultaneously to a master device 120. In another embodiment of such anantenna 312 pair, both antennas 312 may be coupled to one sensor 310(i.e., one sensor 310 with two antennas 312), wherein the sensor 310 mayswitch antennas 312 between messages, or between individual elements ofa message, to communicate measurements from both antennas 312substantially simultaneously to a master device 120; for example, in anembodiment using BLE, the sensor 310 may switch antennas 312 between theindividual data packets of a connection event. In yet another embodimentwherein a sensor 310 is connected to multiple antennas 312, instead ofswitching between each antenna 312, two or more antenna 312 outputs maybe fed in parallel to the sensor 310, allowing the sensor 310 to obtainmeasurements from antennas 312 substantially simultaneously (e.g., asdescribed herein in Section C.9.e).

In a variation of the illustrated embodiment, 312A and/or 312B may bedirectional and/or omnidirectional antennas wherein any divider ispresent that attenuates or reflects signals between antennas 312A and312B (e.g., such as a ground plane, sheet metal, wood, water, etc.).Additionally, multiple thresholds may be defined, such that there aremultiple zones 400 within the receive range of the antennas. Forpurposes of disclosure, the antennas 312, the zones 400 and the virtualboundary 410 are provided with letter designations to aid correlationamong the zones 400 and virtual boundaries 410 to one or more antennas312. It should be understood that the zones 400, virtual boundaries 410and the one or more antennas 312 provided with letter designations arenot limited to any one type of configuration—for instance, for anantenna designated 312A in an illustrated embodiment, any embodiment ofantenna 312 may be implemented in conjunction with the antenna 312,including the embodiment shown in the illustration. For instance, ratherthe antenna 312A being a directional antenna configuration, the antenna312A may be an omnidirectional antenna configuration.

In the illustrated embodiments of FIGS. 10 and 11, with the antennas312A, 312B and the device 110 being within reception range of eachother, the relative position between the antenna 312 and device 110 canbe in Zone 400A or in Zone 400B. If the antennas 312A, 312B and thedevice 110 are not within reception range of each other (outside of Zone400A and outside of Zone 400B), the relative position between theantennas 312A, 312B and device 110 is unknown. In the two directionalantenna example, assuming the device 110 is in range, it may be possibleto determine which side of the virtual boundary 410A-B a device 110 islocated. Depending upon the selected thresholds used to determine Zone400A or Zone 400B, it may be possible for the device 110 to bedetermined to be in both zones simultaneously (e.g., along or close tothe virtual boundary), in which case, the position of device 110 may beconsidered to be unknown, in both zones, in a prior determined zone, orin a new “inbetween” zone (designated 400C in the illustrated embodimentof FIG. 10). Similar inbetween zones may be detected with respect toboundaries between zones in one or more embodiments described herein.

B.4 Three Directional Antennas with Three Zones and Three VirtualBoundaries

One embodiment with three antennas 312 forming a triplet with threevirtual boundaries 410 is shown in FIG. 12. In the illustratedembodiment, three spatially correlated directional antennas 312A, 312B,312C are provided. The directional antennas 312A, 312B, 312C areconfigured with antenna boresights oriented opposite to each other,yielding three zones 400A, 400B, 400C, as well as three virtualboundaries 410A-B, 410B-C, 410A-C, between the three zones 400A, 400B,400C. In one embodiment of such an antenna 312 triplet, each antenna 312may be coupled to a sensor 310 (i.e., three sensors 310 each with oneantenna 312), wherein each sensor 310 may communicate measurementssubstantially simultaneously to a master device 120. In anotherembodiment of such an antenna 312 triplet, both antennas 312 may becoupled to one sensor 310 (i.e., one sensor 310 with three antennas312), wherein the sensor 310 may switch antennas 312 between messages,or between individual elements of a message, to communicate measurementsfrom both antennas 312 substantially simultaneously to a master device120; for example, in an embodiment using BLE, the sensor 310 may switchantennas 312 between the individual data packets of a connection event.In yet another embodiment wherein a sensor 310 is connected to multipleantennas 312, instead of switching between each antenna 312, two or moreantenna 312 outputs may be fed in parallel to the sensor 310, allowingthe sensor 310 to obtain measurements from antennas 312 substantiallysimultaneously (e.g., as described herein in Section C.9.e).

In a variation of the illustrated embodiment, 312A, 312B and/or 312C maybe directional and/or omnidirectional antennas wherein any divider ispresent that attenuates or reflects signals between antennas 312A, 312B,and 312C (e.g., such as a ground plane, sheet metal, wood, water, etc.).Additionally, multiple thresholds may be defined, such that there aremultiple zones within the receive range of the antennas 312A, 312B,312C.

In one embodiment, with the antennas 312A, 312B, 312C and the device 110within reception range of each other, the relative position between theantennas 312A, 312B, 312C and device 110 can be in in Zone 400A, Zone400B or in Zone 400C. If the antennas 312A, 312B, 312C and the device110 are not within reception range of each other (outside of Zone 400A,Zone 400B and outside of Zone 400C), the relative position between theantenna and device 110 is considered unknown with respect to antennas312A, 312B, 312C.

B.5 Two Directional Antenna Pairs with Four Zones and Two VirtualBoundaries

One embodiment with two pairs of antennas 312 with two virtualboundaries 410 is shown in FIGS. 13-14. In the illustrated embodiment,four spatially correlated directional antennas, designated 312A, 312B,312C, 312D, are provided. The antennas 312A, 312B, 312C, 312D arelocated at a right angle to each other, yielding four zones 400A, 400B,400C, 400D, as well as two virtual boundaries 410A-B, 410C-D. In oneembodiment of such a pairing of antenna 312 pairs, each antenna 312 maybe coupled to a sensor 310 (i.e., four sensors 310 each with one antenna312), wherein each sensor 310 may communicate measurements substantiallysimultaneously to a master device 120. In another embodiment of such apairing of antenna 312 to form a pair, antennas 312 may be coupled toone sensor 310 (e.g., one sensor 310 with four antennas 312), whereinthe sensor 310 may switch antennas 312 between messages, or betweenindividual elements of a message, to communicate measurements from bothantennas 312 substantially simultaneously to a master device 120; forexample, in an embodiment using BLE, the sensor 310 may switch antennas312 between the individual data packets of a connection event. In yetanother embodiment wherein a sensor 310 is connected to multipleantennas 312, instead of switching between each antenna 312, two or moreantenna 312 outputs may be fed in parallel to the sensor 310, allowingthe sensor 310 to obtain measurements from antennas 312 substantiallysimultaneously (e.g., as described herein in Section C.9.e). In yetanother embodiment of such a pairing of antenna 312 pairs, a combinationof the prior two embodiments may be used, consisting of a pair ofsensors 310 that each are coupled with two antennas 312.

In a variation of the illustrated embodiment, 312A, 312B, 312C, and/or312D may be directional and/or omnidirectional antennas wherein anydivider is present that attenuates or reflects signals between pairingsof antennas 312A, 312B, 312C, and 312D (e.g., such as a ground plane,sheet metal, wood, water, etc.). Additionally, multiple thresholds maybe defined, such that there are multiple zones within the receive rangeof the antennas 312A, 312B, 312C, 312D.

In the illustrated embodiments of FIGS. 13-14, with the antennas 312A,312B, 312C, 312D and the device 110 being within reception range of eachother, the relative position between the antennas 312A, 312B, 312C, 312Dand device 110 can be in Zone 400A, Zone 400B, Zone 400C, or Zone 400D.If the antennas 312A, 312B, 312C, 312D and the device 110 are not withinrange of each other (outside of Zone 400A through 400D), the relativeposition between the antennas 312A, 312B, 312C, 312D and device 110 isconsidered unknown with respect to antennas 312A, 312B, 312C, 312D. Inthe two directional antenna example, assuming the device 110 is inrange, it may be possible to determine which side of the virtualboundaries 410A-B, 410C-D a device 110 is located, as depicted in theillustrated embodiment of FIG. 14.

B.6 Three Directional Antenna Pair with Six Zones and Three VirtualBoundaries

One embodiment with a triplet of pairs of antennas 312 is shown in FIG.15. In the illustrated embodiment, six directional antennas are providedand designated 312L, 312R, 312T, 312B, and 312F with 312A (aft notshown) that are located at a right angle to each other, yielding sixzones 400L, 400R, 400T, 400B, and 400F with 400A (aft not shown), aswell as three virtual boundaries (not shown). Embodiments of such atriplet of antenna 312 pairs may be constructed using any of thepreviously described sensor 310 and antenna 312 combinations and/ormethods previously disclosed. In a variation of the illustratedembodiment, 312L, 312R, 312T, 312B, 312F, and/or 312A may be directionaland/or omnidirectional antennas wherein any divider is present thatattenuates or reflects signals between pairings of antennas 312L, 312R,312T, 312B, 312F, and 312A (e.g., such as a ground plane, sheet metal,wood, water, etc.). Additionally, multiple thresholds may be defined,such that there are multiple zones within the receive range of theantennas 312L, 312R, 312T, 312B, 312F, and 312A.

B.7 N Pairs of Directional Antennas

Additionally, N pairs of directional antennas 312 may be combined tocreate N virtual boundaries 410 along with 2N zones 400. These virtualboundaries 410 may be configured in any orientation to create an arrayof zones 400, such that it may be detected in which zone 400(partitioned by the virtual boundaries 410) a device 110 is located.Additionally, multiple thresholds can be defined, such that there aremultiple zones 400 within the receive range of the antennas 312.

It should further be understood that although pairs of antennas 312 or Nantenna 312 are described as separate antennas 312, an antenna 312 inaccordance with one embodiment may itself be comprised of two or moreantennas 312. As an example, the antennas 312A, 312B, 312C, 312D in theillustrated embodiments of FIGS. 13-14 may be considered a singleantenna 312 with multiple zones 400 and multiple virtual boundaries 410.

B.8 3D Space Acknowledgment

Realizing that the virtual boundaries 410 are actually similar to planesin 3D space, in one embodiment, a 3D space may be divided into zones 400by placing directional antennas 312 in appropriate locations andorientations.

C. Example Systems

Several techniques and configurations may be utilized, individually ortogether, to enhance the likelihood that the actual relative location ofa device 110 can be correctly identified within a system 100 inaccordance with one embodiment. For instance, one or more aspects of anembodiment described herein may be implemented in conjunction withanother embodiment described herein. It should also be understood thatone or more aspects described in conjunction with the other embodimentmay be absent in some configurations. In this way, a system 100 inaccordance with one embodiment may include both any aspect or featurefrom a first embodiment of the present disclosure and any aspect orfeature of another embodiment.

C.1 Distributed Antenna Connection/Processing

When using multiple antennas 312, they may be connected to one ormultiple transmitters or receivers (e.g., an electronic system component200). The distribution, or not, of electronics may facilitate afunctional or economic advantage. For example, multiplexing more thanone antenna 312 to a single set of electronics may reduce overallcomplexity and cost associated with the electronics. Alternately, undercertain circumstances, it may be beneficial for the electronicsconnected to the antennas 312 to be distributed, for instance since theconnection between the antenna 312 and associated electronics may beprohibitively lengthy.

C.2 Outside Known Zones is Useful

Useful information may be obtained when a device 110 is located outsideall detected zones 400 of a system 100. For example, if a device 100 isnot physically located close enough to a piece of equipment 140 to be inany of the zones 400, then the device 110 may not be authorized toperform certain activities or access certain features.

Additionally, useful information may be obtained when a device 110 islocated in multiple detected zones 400 of a system 100. For example, ifa device 110 is located on or near a virtual boundary, the system 100may determine that the position of device 110 is unknown, in more thanone zone, in a prior determined zone, or in another zone that representspresence in multiple zones (e.g., “in-between”), or any combinationthereof, each of which may result in different authorization to performcertain activities or access certain features.

C.3 Compound Zones

In one embodiment, one or more zones 400 may be overlapped, creating acompound zone 402. The compound zone is designated as zone 402 in theillustrated embodiment of FIG. 16—but it should be understood that thecompound zone 402 may be considered a zone 400 in other embodiments tofacilitate discussion. In the illustrated embodiment of FIG. 16, twocompound zones 402BE, 402CF are shown—although more or fewer compoundzones may be realized.

Obtaining confirmation that a device 110 is detected within the compoundzone 402, (within all of the zones 400 which make up a compound zone402) increases the likelihood that the device 110 is actually locatedthere. In the illustrated embodiment, compound zone 402BE is created bythe overlap of zone 400B and zone 400E. Compound zone 402CR is createdby the overlap of zone 400C and zone 400F.

C.4 Additional Zones by Combining Adjacent Antennas

In one embodiment, depicted in FIG. 17, rather than using aconfiguration of two spatially correlated directional antennas 312, apair whose antenna boresights are oriented opposite to each other, anantenna configuration may be implemented where adjacent antennas arecombined as one. This can create zone shapes 420AD, 420AB, 420BC, 420CDthat can be used for additional functionality. Converting between theseconfigurations may be accomplished by using switching of signals to theantennas. The zone shapes 420, similar to the compound zone 402, may beconsidered a zone 400 in other embodiments to facilitate discussion.

In the illustrated embodiment of FIG. 17, for example, the 4-zone (400A,400B, 400C, 400D) two-directional antenna pair sensor 312A, 312B, 312C,312D described in conjunction with FIG. 4, may be expanded to an 8-zonetwo-directional antenna pair sensor by switching between configurations,as shown above. In this way, the sensor 310 may include eight zones400A, 400B, 400C, 400D, 420AD, 420AB, 420BC, 420CD. Virtual boundaries410 may be defined by the zone shapes 420AD, 420AB, 420BC, 420CD, asshown in the illustrated embodiment of FIG. 17 with virtual boundaries410AD-BC, 410AB-CD.

In one embodiment, the illustrated embodiment may be extended to threedimensions by combining additional antennas 312 pointing on the up ordown directions, and then pointing the beam into any sector of thesphere surrounding the sensor 312 (by selecting one, two, or threeantennas).

C.5 Combining Zones

Combining/switching antennas 312 using analog circuitry may result inbehavior described in conjunction with FIG. 17. Combining two or moreantennas 312 digitally (e.g., by using the maximum, average,transformed, etc., measured RSSI) may result in the consolidation(combination) of their corresponding zones 400 into one larger zone 400.

C.6 Virtual Boundary Creation and Zone Determination

Virtual boundaries 410 may be created via the differential of a givensignal received from multiple spatially correlated and/or co-locatedantennas 312 (with appropriate orientations, as described above). In oneembodiment, the differential is taken using opposing antennas 312;however, the differential may be taken from one or more physicalantennas 312 (e.g. adjacent or opposing) or virtual antennas 312 (e.g.,antennas that are created by combining multiple physical antennas 312).For example, using the RSSI as measured from opposing antennas 312A and312B, a device 110 may be detected in either zone 400A or zone 400B,with the device 110 being present in zone 400A, if the RSSI is higher in400A and lower in 400B (i.e., 400A-400B>0), and vice versa, in zone400B, if the RSSI is higher in 400B and lower in 400A (i.e., B-A>0).Additionally, for any given antenna 312, a minimum and/or maximumthreshold may be utilized to overcome the back/side lobe 316, 318 versusmain lobe 314, to provide confidence that the device 110 is presentwithin the zone 400 (since it may be unclear whether the device 110 isin the zone 400, but far away, or nearby, but outside the zone 400).Similarly, for any given antenna pair 312, a minimum difference may beutilized to provide confidence that a device 110 is in one zone 400 orthe other zone 400 (e.g., the zone 400 may be reported as unknown, ifnot satisfied). If the device 110 is not present in any zone 400, thenthe device 110 is either outside the range of the zones 400, or isbetween zones 400 (e.g., within the boundaries). Additional techniquesmay be employed to more precisely locate devices 110 (and/or providemore accuracy/confidence) that are indicated as being present in aparticular zone 400, including fingerprinting, trilateration,triangulation (coarse or fine), hysteresis, and so on. Alternative toRSSI, as indicated elsewhere, other techniques may be used to determinethe zone 400 in which a device 110 is located (e.g., computing theprobability that a device 110 is in a particular zone 400, etc.) usingthe virtual boundary (differential) approach. RSSI and alternatives maybe combined (e.g., RSSI+probability) to enhance accuracy.

In addition to the above, techniques may be employed to remove or reducethe probability of illegal zone transitions from the set of possiblezones 400 when tracking a device 110 as it moves through the system 100,such as time- or value-based hysteresis, maximum-change-over-time,accelerometer/velocity/step counting, adjacency matrices, and so on.

As described elsewhere, multiple sensors 310 may be combined to isolatedevices 110 to a particular zone 400 (even with sensors 310 that do notcreate a virtual boundary 410). With the use of additional techniques,devices 110 may be positioned more precisely within particular zones400.

C.7 Subtracting Background Power

In one embodiment, there are many transmitters beyond just those thatmay be part of a particular microlocation system 100 (e.g., there aremany Wi-Fi-enabled laptops in a particular area, many BLE devices in aroom, etc.). Those transmitters may transmit (or leak) signals while theRSSI for a particular device 110 is being measured, resulting invariations in the measured RSSI due to other transmitters. To reducethis variability (and thus, increase measurement accuracy andprecision), the measured background power may be subtracted from themeasured RSSI. The background power may be measured in any appropriateunit (e.g., watts) and converted to/from RSSI units (e.g., dB) usingstandard mathematical relationships (e.g., power=10̂[db/10], db=log10(power)*10, etc.). RSSI is converted to power, and then the backgroundpower is added, subtracted, averaged, transformed (e.g., probabilitydistribution or estimation, etc.), and/or filtered (including time/valuebased hysteresis), or any combination of these, or other techniques, asappropriate, prior to returning to RSSI units. Alternatively, thebackground power may be converted to RSSI units and then added,subtracted, averaged, transformed (e.g., probability distribution orestimation, etc.), and/or filtered (including time/value basedhysteresis), or any combination of these, or other techniques, asappropriate. The background power may be measured one or more timesbefore, during, and/or after a signal is received; those measurementsmay then be averaged (e.g., for all time/since power-up, moving [linear,exponential, etc.], etc.), min′d, max′d (e.g., peak hold), filtered toremove outliers/inconsistencies (including time/value based hysteresis),transformed (e.g., probability distribution or estimation, etc.), or anycombination of these, or other techniques, to obtain the backgroundpower.

Background power measurements/estimations may be shared or distributedacross antennas/sensors to determine a sensor- or system-wide backgroundpower measurement (using any combination of the above or other methods),which is then used in conjunction with, or instead of, individualantenna or sensor background power measurements.

C.8 Using Background Power to Identify Unreliable RSSI Measurement

Upon receipt of a signal, with a measured RSSI and observed backgroundpower, if the background power is outside of a predefined threshold orrange, in absolute terms (e.g., if background RSSI is greater than X,less than Y, outside X . . . Y, or inside X . . . Y, etc.) or inrelative terms (e.g., the measured RSSI and background RSSI are tooclose or too far apart, etc.), the measured RSSI may be ignored,considered more relevant, or considered less relevant. For example,relevancy may be reflected in a zone determination orlocation/positioning algorithm by increasing or decreasing one or moreweights associated with one or more measurements.

C.9 Use of Multiple Measurements to Mitigate Multipath Variability

RSSI, and AoA based on comparing the signal strength from multipleantennas, may be naturally compromised by multipath interference (alsoreferred to as fading). Fading is the result of the signal from thesource taking more than one path, due to the presence of reflectingand/or blocking surfaces. FIG. 44 shows a characteristic of fading in asmall region where the aperture is moved over a range significant to thesize of the wavelength (perhaps 10 wavelengths). Fading may cause signalstrength to vary in a way that is uncorrelated with the antenna pattern,so that RSSI and AoA techniques may exhibit errors as the actual signaldeviates from ideal received signal strength. One embodiment accordingto the present disclosure may use two methods, alone or in conjunctionwith each other, to mitigate fading and other environmental effects thatmay affect signal characteristics (e.g., received power, angle, time offlight, etc.). For example, some characteristics of the environment thatmay cause receive power to vary from the transmitter to receiverinclude, but are not limited to: a) heading in attitude coordinates(heading, pitch, roll), measured at the transmitter, of the line goingtowards the receiver (i.e., due to antenna gain pattern and polarizationpattern); b) heading in heading coordinates (heading, pitch, roll),measured at the receiver, going towards the transmitter (i.e., due toantenna gain pattern and polarization pattern); c) frequency variationin antenna gain at the transmitter and at the receiver; d) attenuationdue to objects that are in the path between the devices; e) attenuationdue to objects that are in the near field of the antenna (e.g. hands,purses, etc.) that detune the antenna; f) objects that reflect andchannel power (e.g. nearby walls, ceilings, cars, etc.). Some of theseobjects move (e.g., car doors, garage doors, etc.); g) fast fading, orspikes, at specific frequencies at specific narrow locations due toreflections off objects causing destructive, or constructive,interference, respectively; h) diffraction as RF bends around objects.

The characteristic of many faded signals approximately follows Rayleighprobability functions, as shown in FIG. 45.

C.9.a Multipath Mitigation by Combining the Results of Low-CorrelatedChannels

Multipath can be mitigated by combining the results from signals thathave low correlation. The present disclosure provides ways of combiningthe results of signal strength comparisons from transmitted signals thathave a frequency separation wide enough to de-correlate the fadingbetween radio channels. This is referred to as having channel separationwider than the correlation bandwidth. For example, with BLE, the resultsof the measurements obtained across the various channels may becombined.

C.9.b Multipath Mitigation by Combining the Results of Low-CorrelatedPolarization Channels

Similar to mitigation by combining the results of low-correlatedchannels, correlation can be reduced by using antennas 312 that areco-located, but have low polarization correlation. One way to combinemultiple polarizations is to use circular polarization for eitherreceive or transmit aperture with linear polarization on the opposingend (transmit or receive).

C.9.c Method of Combining the Results from Low-Correlation Channels

Multipath fading follows a probability distribution referred to as aRayleigh (shown in FIG. 45). As can be appreciated, the probability of asingle signal strength measurement being very low is small compared tothe probability of measuring a typical signal strength. Yet, there is avery large potential variation in signal strengths due to fading, so asingle measurement can result in large errors. As such, one aspect ofthis disclosure is to use a series of low-correlation measurements toimprove the accuracy. Low correlation can be achieved with frequency orpolarization. Combining can be done with each of the below methods,either alone, or in combination.

Method 1—Peak Hold

In this method, the peak received signal is held over some range oftime. The underlying theory is that the peak of the faded signal is asingle value. This method is not considered computationally complex, butit does depend on intercepting a signal that happens to have the peakamplitude, which has a low probability of occurrence.

Method 2—Weighted-Time (Moving) Average

Combing measurements may involve taking measurements over a period oftime. As such, more recent measurements are generally more relevant. So,use of a weighted average of signals with higher weight placed on morerecent measurements may facilitate mitigating multipath fading. This maybe done either as a preferably exponential de-weighting or potentiallylinear de-weighting. In one embodiment using BLE, measurements acrossall channels are combined using an exponential moving average, where theweighting may be fixed, a function of the number of valid measurementsthat have been received over a number of measurement intervals (e.g.,the last N valid measurements) or period of time, a function of thevariability or consistency relative to one another or to the currentaverage of measurements over a number of measurement intervals or periodof time, a function of the current average, or any combination thereof.

Method 3—Probability Function Estimation

By taking a series of measurements, the Rayleigh function may beestimated. This method may overcome a potential weakness of Method 1,but may utilize more measurements. Increasing the number of measurementsincreases the accuracy of the estimation.

A combined method, for example, may more heavily weight more recentmeasurements used for the estimation or peak hold.

Method 4—Other Methods

Other methods may be used, separately or in combination with, the aboveand below methods to combine measurements. For example, the measurementsmay be combined as part of simpler approaches (instantaneous or methodsdescribed in conjunction with the discussion of virtual boundarycreation and zone determination) or more advanced approaches, such asfingerprinting, particle filter, kalman filter, time- and/or value-basedhysteresis, maximum-change-over-time, or other algorithms.

Additionally, the above may be used in conjunction with othersystem-level combinatorial approaches to further provide confidence inthe correctness of a particular measurement, such asacceleration/velocity/step counting, ultrasonic, and known proximity(i.e., measurement at UI interaction [e.g., button push] is X, thereforeit can't be Y, etc.).

Due to environmental effects, it is possible that signal characteristicsfrom one or more antennas 312 may not be determined, because the outputfrom the antenna 312 is invalid or missing; however, signalcharacteristics from other antennas 312 may be determined. In caseswhere one or more signal characteristics are missing/invalid from one ormore antennas 312, the system 100 may choose to, for eachmissing/invalid signal characteristic that is not derived from othersignal characteristics: (a) not update the corresponding output signal(e.g., average, moving average, exponential moving average, max, min,etc.); (b) not update the output signal, but increment a missingreadings indicator, and when the missing readings indicator reaches athreshold (e.g., more than 20 missing measurements), mark the outputsignal as invalid; (c) update the output signal with a default value;(d) update the output signal with a default value, but increment amissing readings indicator, and when the missing readings indicatorreaches a threshold (e.g., more than 20 missing measurements), mark theoutput signal as invalid, immediately with a default value, or ramp theoutput signal to a default value over a number of measurement intervals;and/or (e) mark the corresponding output signal as invalid. In caseswhere one or more signal characteristics are missing/invalid from one ormore antennas 312, the system 100 may choose to, for eachmissing/invalid signal characteristic that is derived from one or moreother signal characteristics (e.g., a differential, a distance, a timeof flight, etc.): (a) use current output signals corresponding tomissing/invalid signal characteristics to determine the derived signalcharacteristic; (b) use last known signal characteristic valuescorresponding to missing/invalid signal characteristics to determine thederived signal characteristic; and/or (c) do not update the outputsignals of derived signal characteristics corresponding tomissing/invalid signal characteristics (in any of the ways describedabove for output signals for non-derived signal characteristics, e.g.,after some number of intervals in which an output signal update did notoccur, the output signal may be marked invalid). Given combinations ofthe above, the output signals may additionally allow the system 100 tocontinue to determine the position of the portable device 110, or toproperly indicate that a portable device 110 position may not bedetermined, during periods of time in which signal characteristics aremissing or invalid.

C.9.d Multipath Mitigation by Using Spatially Low-Correlation Channels

This method may use separate apertures (antennas 312) that are separatedwidely enough to have low correlation in their received signal strength.This is also referred to as spatial diversity. This embodiment of thisdisclosure may use a combination of multiple signal strengths forapertures that substantially cover the same region. In other words, thecoverage overlaps. The redundancy of this method may naturally reduceerrors by building an estimate of the position based on weightingresults that are estimated to be more reliable—for example, using Method2 or 3, above.

C.9.e Use of a Single Aperture with One or More Propagation Directions.

One aspect of this disclosure is to determine RSSI measurements, ordirection of arrival of a signal by comparing the signal amplitudereceived, from different apertures. The signal strength from twodifferent apertures may become de-correlated as the apertures becomespatially separated. With that basis, if two apertures can occupy thesame space, then spatial de-correlation can be minimized or reduced. Oneway of achieving this is to use a set of individual radiators (such asdipole antennas) and to simultaneously electrically combine them usingdifferent phases. For example, two antennas can be separated by a ¼wavelength and fed simultaneously with 0/90 degrees and 90/0 degrees, asshown in the illustrated embodiment of FIG. 46. This may result in twodistinct patterns, as shown in the illustrated embodiment of FIG. 47.

This embodiment can be extended to achieve steering in four quadrants ormore by adding more antennas 312 and more phase controls.

C.9.f Distance Measurement/Rangefinding

RSSI may be used to approximate a distance from a particular receiver(rangefind); because the distance estimate becomes less accurate as thedistance increases, the range (distance) may be communicated along withcomputed error bounds (e.g., −50%/+100%). Secure ranging approaches maybe used, such as distance bounding untrusted (unauthenticated) devices(using traditional time-of-flight, adapted for use with RSSI, adaptedfor use with AoA, or any combination of these, or other approaches).Additionally, zone distance (e.g., from center, an edge, etc.) to aknown point may also be used to approximate distance. Additionaltechniques may be used for rangefinding as well, and may be combined toachieve greater robustness, accuracy, and/or precision (e.g.,trilateration, triangulation, time-of-flight, etc.).

To deliver secure microlocation and/or ranging, one or more aspects ofthe system may be implemented in conjunction with one or more aspects ofthe security model described in U.S. Provisional Patent Application No.62/413,966, entitled SYSTEM AND METHOD FOR AUTHENTICATING ANDAUTHORIZING DEVICES AND/OR FOR DISTRIBUTING KEYS, filed Oct. 27, 2016,to Smith et al. and U.S. patent application Ser. No. 15/796,180,entitled SYSTEM AND METHOD FOR AUTHENTICATING AND AUTHORIZING DEVICES,filed Oct. 27, 2017, to Smith et al.—the disclosures of which areincorporated herein by reference in their entirety.

C.10 Angle-of-Arrival (AoA)

Angle of arrival (AoA) measurement is a method for determining thedirection of propagation of a radio-frequency wave incident on anantenna array 312. AoA may determine the direction by measuring the TimeDifference of Arrival (TDOA) at individual elements of the array 312;from these delays, the AoA can be calculated. Using phased ormulti-element antennas 312 (omni-directional or directional) capable ofdetermining the angle of arrival of the transmitted signal, techniquessuch as triangulation can be used to supplement device locationinformation. With a fine-grained angle of arrival measurement (asmeasured across multiple sensors 310), more precise positioning may bedetermined.

Many RF environments are very noisy (e.g., the 2.4 GHz spectrum) andthus, the received AoA may also be very noisy. Combined with zoneinformation (or not), additional confidence in the accuracy of thetriangulated position may be gained with agreement; the additionalpositioning information may enable the system 100 to determine theposition of a device 110 within a zone 400 with more precision.

Additionally, it may be possible for the transmitter to adjust thedirectionality of its antenna 312 using beam steering; this may be doneto vary the AoA in a particular pattern at the receiver, so as to enablemore accurate positioning. Additionally, the receiver may adjust thedirectionality of its antenna(s) 312 in a similar way, for similarpurposes.

C.11 Coarse Angle-of-Arrival (AoA)

A coarse Angle of Arrival scheme may be implemented by utilizing theinherent positioning of the sensor antennas 312. For example, a onedirectional antenna 312 pair (two zone) may provide a 180-degreeangle-of-arrival measurement precision. A two directional antenna 312pair (four zone) may provide a 90-degree angle-of-arrival measurementprecision and a four directional antenna 312 pair (eight zone) mayprovide a 45 degree angle of arrival measurement precision. Treatingthis as a coarse AoA approach allows the system to determine in whichzone a particular device resides; similar to fine-grained AoA, whereinfor example triangulation may be used to position a device 110, withthis system 100, coarse AoA, using a process similar to triangulation,determines in which zone 400 (overlapping fields) a device 110 resides.

C.12 Circular Polarization

In one embodiment, the system 100 may use linearly polarized antennas312. Such antennas 312 are considered small. In real worldcircumstances, signals reflect off all sorts of things, allowing anantenna 312 to eventually receive signals at reduced strength(theoretically, a linear horizontally polarized transmission may not bereceived by a linear vertically polarized antenna). As a result,linearly polarized receiver antennas 312 may perform vastly differentdepending upon the orientation of the transmitter, which can affect theability of the system 100 to accurately and consistently measure RSSI,AoA, and/or other attributes (as people or devices move around or changeorientations in someone's hand).

Circular polarized antennas 312 do not depend as much upon theorientation of the transmitter, enabling more accurate and consistentmeasurement of RSSI, AoA, and/or other attributes.

The system 100 in accordance with one embodiment described herein mayutilize circular polarized antennas 312; however, they may also uselinear polarized antennas 312. Additionally, other polarizations may beutilized, depending upon established system goals.

C.13 Environment Geometry and Materials

The physical geometry of the environment in which antennas 312 areplaced affects their radiation pattern, and thus influences the zones400 they generate. In many cases, this is a possible advantage, allowingcomplex zone shapes 400 to be formed due to the materials and shape ofthe thing in which the antennas 312 are located (e.g. using the metalshell of a vehicle, or the dense material of a desk surface, etc.).

C.14 Environment and Obstruction Determination

Measured RSSI and background power patterns detected at various antennas312 and/or sensors 310 in the system 100 may allow the system 100 todetect its environment or obstructions in the environment and alter itspositioning approach. For example, the system 100, given knowledge thata device 110 is present at a known location (such as a vehicle doorhandle), and given RSSI measurements from antennas 312A, 312B, 312 C,and 312D, determine that because 312A, 312B, and 312C are high, and 312Dis low, when 312C is expected to be low, there is another vehiclenearby. For example, the background noise may be very high, and thus,the system 100 may switch to an alternate positioning algorithmoptimized for high-noise environments.

D. Additional Embodiments

In the following embodiments, any one or more of the transmitter, thereceiver, the antenna 312 and the device 110 may be in a fixed orportable location.

The method and system described above and shown in the followingembodiments may be each implemented using multiple methods, including,but not limited to:

-   -   An embodiment using BLE.    -   An embodiment using BLE and RSSI.    -   An embodiment using BLE, RSSI, and trilateration.    -   An embodiment using BLE, RSSI, trilateration, and triangulation.    -   An embodiment using BLE, RSSI, trilateration, triangulation, and        time-of-arrival.    -   An embodiment using UWB.    -   An embodiment using BLE and UWB.    -   An embodiment using BLE and NFC (near field communication).    -   An embodiment using BLE and LF (low frequency).    -   An embodiment using BLE and LF and NFC.    -   All of the above, and all variations, in the context of a        microlocation system.    -   Further a sniffing microlocation system may be implemented in        accordance with one or more embodiments described herein and as        described in the disclosures of U.S. Provisional Patent        Application No. 62/323,262 entitled SYSTEM AND METHOD FOR        ESTABLISHING REAL-TIME LOCATION, filed Apr. 15, 2016, to Stitt        et al. and U.S. patent application Ser. No. 15/488,136 entitled        SYSTEM AND METHOD FOR ESTABLISHING REAL-TIME LOCATION, filed        Apr. 14, 2017, to Stitt et al.—the disclosures of which are        incorporated herein by reference in their entirety.    -   Further examples, possibly employing secure microlocaiton, may        be based on one or more embodiments described in as described        U.S. Provisional Patent Application No. 62/413,966, entitled        SYSTEM AND METHOD FOR AUTHENTICATING AND AUTHORIZING DEVICES        AND/OR FOR DISTRIBUTING KEYS, filed Oct. 27, 2016, to Smith et        al., U.S. patent application Ser. No. 15/796,180, entitled        SYSTEM AND METHOD FOR AUTHENTICATING AND AUTHORIZING DEVICES,        filed Oct. 27, 2017, to Smith et al. and U.S. Provisional Patent        Application No. 62/323,262 entitled SYSTEM AND METHOD FOR        ESTABLISHING REAL-TIME LOCATION, filed Apr. 15, 2016, to Stitt        et al.—the disclosures of which are incorporated herein by        reference in their entirety.

D.1 Energy Access Embodiment

One embodiment may allow for detection of a device 110 in proximity toan energy access point. The energy access point may be mobile or in afixed location. An electric car charging station, for example, mayincorporate an energy access point. A user of an energy access point maytransport a device 110 within a zone 400 or compound zone 402 created bya sensor 312 or sensors 312 with antennas located in or near the energyaccess point. Recognition of the presence of a device 110 by the sensoror sensors 312 may, for example, possibly authorize the user to performcertain functions associated with an energy access point, such asphysical access to connection points, adjustment of energy dispensing,enabling or disabling electrical circuits or outlets, targetedmarketing, and so on. Additional utilities or amenities associated withthe energy access point can be enabled or disabled in a similar manner.

D.2 Data Access Embodiment

One embodiment may allow for detection of a device 110 in proximity to adata access point. The data access point may be mobile or in a fixedlocation. An electric car charging station, for example, incorporates adata access point. A user of a data access point may transport a device110 within a zone 400 or compound zone 402 created by a sensor orsensors 312 with antennas located in or near the data access point.Recognition of the presence of a device 110 by the sensor or sensors 312may, for example, possibly authorize the user to perform certainfunctions associated with a data access point, such as physical accessto connection points, adjustment of access to data/information, targetedmarketing, and so on. Additional utilities or amenities associated withthe data access point can be enabled or disabled in a similar manner.

D.3 Door Microlocation Embodiment

One or more zones 400, compound zones 402, or virtual boundaries 410 canbe used to determine on which side of a door (if either) a device 110 islocated. A door is meant to include manual or automatic operation,single panel, sectional or roller constructions, and hinged, sliding ormoving on tracks. The antennas 312 creating the zones 400, or compoundzones 402, may be embedded within the door lock, affixed to the dooritself, or to the related structures near the door, such as the ceilingand walls in proximity to or the trim around the door. Device locationinformation may be used to control the locking, unlocking, opening,closing, or non-movement, of a door, as well as noting the relativemovement of a device 110 through the doorway targeted marketing, and soon. An example of such a configuration is depicted in the illustratedembodiment of FIG. 15, including a wall 141 and a door 142 in a closedposition, forming a physical boundary 411 relative to two zones 400.

One embodiment for an automatic garage door may trigger the opening ofthe garage door if the car (device) and mobile phone (device) isdetermined to be in proximity to the door, or some combination thereof.

D.4 Work Surface Microlocation Embodiment

One embodiment may allow for detection of a device 110 in proximity to awork surface. The work surface may be mobile or in a fixed location, maybe any shape, and may be horizontal or at any angle from horizontal(e.g., desks, drafting tables, whiteboards, etc.). A desk, for example,often incorporates a work surface. A user 10 of the work surface maytransport a device 110 within a zone 400 or compound zone 402 created bya sensor or sensors 310 with antennas 312 located in or near the worksurface (e.g., left, right, above, below, in front, behind, on, inside,near, far, etc.). Recognition of the presence of a device 110 by thesensor or sensors 312 may, for example, possibly authorize the user toperform certain functions associated with the work surface, such asphysical adjustment of the work surface position (e.g., height, tilt,etc.), record work surface usage (presence and/or duration), assist inthe location of devices 110 (and their users 10), targeted marketing,and so on. Additional utilities (power or data access) or amenities(e.g., lighting, displays, sounds, or access to controls, etc.)associated with the work surface may be enabled or disabled in a similarmanner.

D.5 Furniture Microlocation Embodiment

One embodiment may allow for detection of a device 110 in proximity to apiece of furniture. The furniture may be mobile or in a fixed location.In one embodiment, one or more zones 400, compound zones 402, or virtualboundaries 410 can be used to determine if a device 110 is located inproximity to a piece of furniture (e.g., left, right, above, below, infront, behind, on, inside, near, far, etc.). A user 10 of the furnituremay transport a device 110 within a zone 400 or compound zone 402created by a sensor or sensors 310 with antennas 312 located in or nearthe furniture. Recognition of the presence of a device 110 by the sensoror sensors 310 may, for example, possibly authorize the user 10 toperform certain functions associated with the furniture, such asphysical access to, or adjustment of, the furniture, record furnitureusage (presence and/or duration), assist in the location of devices 110(and their users 10), targeted marketing, and so on. Additionalutilities (power or data access) or amenities (e.g., lighting, displays,sounds, or access to controls, etc.) associated with the furniture maybe enabled or disabled in a similar manner.

Some additional examples of use in furniture include applications tostadium/theater/conference/event/restaurant/hospital/etc. seating forthe purposes of seat determination (am I in the right seat and/or whereis my seat), admissions (as opposed to scanning a tag—including themeparks), where a particular device is located (order fulfillment, userlocation, e.g., in a hospital for consultation, sporting event for fooddelivery, or restaurant for order delivery, retail for customer locationfor use in queuing systems, etc.).

D.6 Carrel, Cubicle, Stall, Shelter, Kiosk, Etc.—MicrolocationEmbodiment

In one embodiment, one or more zones 400, compound zones 402, or virtualboundaries 410 can be used to determine if a device 110 is locatedinside, outside, or within a particular zone 400 of a carrel, cubicle,stall, shelter, kiosk, etc. A user 10 of the carrel, cubicle, stall,shelter, kiosk, etc., may transport a device 110 within a zone 400 orcompound zone 402 created by a sensor or sensors 310 with antennas 312located in or near the carrel, cubicle, stall, shelter, kiosk, etc.Recognition of the presence of a device 110 by the sensor or sensors 312may, for example, possibly authorize the user 10 to perform certainfunctions associated with the carrel, cubicle, stall, shelter, kiosk,etc., such as physical access to, or adjustment, of the carrel, cubicle,stall, shelter, kiosk, etc., targeted marketing, and so on. Additionalutilities (power or data access) or amenities (e.g., lighting, displays,sounds, or access to controls, etc.) associated with the carrel,cubicle, stall, shelter, kiosk, etc., may be enabled or disabled in asimilar manner.

Some additional examples of use in carrel, cubicle, stall, shelter,kiosk, etc., include applications tostadium/theater/conference/event/restaurant/hospital/theme parks/etc.for the purposes of admissions (as opposed to scanning a tag—includingtheme parks).

D.7 Room Microlocation Embodiment

In one embodiment, one or more zones 400, compound zones 402, or virtualboundaries 410 can be used to determine if a device 110 is locatedinside, outside, or within a particular area inside or outside of a room(e.g., a movie theater viewing room, access to certain facilities/roomsat an airport, hotel, or resort, a particular conference room or office,etc.). A user 10 of the room may transport a device 110 within a zone400 or compound zone 402 created by a sensor or sensors 310 withantennas 312 located in or near the room. Recognition of the presence ofa device 110 by the sensor or sensors 312 may, for example, possiblyauthorize the user 10 to access the room and perform certain functionsassociated with the room, such as physical access to, or adjustment ofthe room, automatic customization of equipment within the room basedupon the users that are present, targeted marketing, and so on.Additional utilities (power or data access) or amenities (e.g.,lighting, displays, sounds, or access to controls, etc.) associated withthe room may be enabled or disabled in a similar manner.

D.8 Building Microlocation Embodiment

In one embodiment, one or more zones 400, compound zones 402, or virtualboundaries 410 can be used to determine if a device 110 is locatedinside, outside, or within a particular area inside or outside of abuilding. A user 10 of the building may transport a device within a zone400 or compound zone 402 created by a sensor or sensors 310 withantennas 312 located in or near the building. Recognition of thepresence of a device 110 by the sensor or sensors 310 may, for example,possibly authorize the user to access the building and perform certainfunctions associated with the building, such as physical access tobuilding control panels or adjustments, targeted marketing, and so on.Additional utilities (power or data access) or amenities (e.g.,lighting, displays, sounds, or access to controls, etc.) associated withthe building may be enabled or disabled in a similar manner.

D.9 Equipment Microlocation Embodiment

One embodiment may allow for detection of a device 110 in proximity to apiece of equipment. Equipment is meant to include manual,semi-automatic, or automatic equipment of mechanical,electro-mechanical, or electrical type (e.g., consumer electronics[toaster, blender, outlet, light switch, fixtures, etc.], appliances[microwave, oven, dishwasher, washing machine, dryer, exerciseequipment, etc.], industrial/farm/heavy equipment [tractor, combine,conveyor, etc.], secure storage boxes and lockers, tools [chainsaw,backhoe, radio, etc.], and much more—including anything to authorizeaccess to or control with a device) The equipment includes any controls(buttons, switches, knobs, levers, etc.) used in conjunction with theequipment. The equipment includes any sensors providing information tothe equipment. The equipment includes any actuators controlled by theequipment. The equipment may be mobile or in a fixed location.

In one embodiment, one or more zones 400, compound zones 402, or virtualboundaries 410 can be used to determine if a device 110 is located inproximity to a piece of equipment. A user of the equipment may transporta device 110 within a zone 400 or compound zone 402 created by a sensoror sensors 310 with antennas 312 located in or near the equipment.Recognition of the presence of a device 110 by the sensor or sensors 312may, for example, possibly authorize the user to perform certainfunctions associated with the equipment, such as physical access to,activation, operation or adjustment of the equipment.

D.10 Interior Vehicle Microlocation Embodiment

In one embodiment, as depicted in the illustrated embodiment of FIG. 19,the system 100 may be implemented in conjunction with a vehicle 500. Thevehicle 500 may include an interior space 502 or cabin, a forwardsection 506, and a rear section 508. In the illustrated embodiment, theinterior space 502 of the vehicle 500 may be conceptualized as fourareas or zones 400: a front left seat zone 510FL, a front right seatzone 512FR, a rear right seat zone 516RR, and a rear left seat zone514RL. The interior space 502 may be conceptualized differently, or maynot be present, depending on the application. The interior space mayinclude a steering wheel 520.

By use of the vehicle, it should be understood that the presentdisclosure contemplates mobile machines which transport people or cargo,including but not limited to wagons, bicycles, motorcycles, automobiles,cars, trucks, trains, trams, ships, boats, aircraft, and spacecraft.

In one embodiment, the placement of two or more perpendiculardirectional antenna 312 pairs in the interior 502 of a vehicle 500 maycreate zones 400FL, 400FR, 400RR, 400RL between seating quads thatcorrespond to passenger seating locations (510FL, 512FR, 516RR, 514RL).These zones 400FL, 400FR, 400RR, 400RL may be used to detect thepresence of mobile phones located in the seating locations usingBluetooth Low Energy. Additional zones may also exist in other systems,such as zones associated with additional seating rows or seats per row(e.g., in larger vehicles, such as vans or busses), rear trunk, rearcargo-area, front trunk, front cargo-area, luggage storage compartments(overhead or below), and so on.

In an alternate embodiment, in which three or more directional antennapairs 312 are used—one to divide the vehicle 500 in half and one betweeneach pair of seats.

In an alternate embodiment, seat determination may be performed usingantennas 312 placed in other positions on the vehicle 500, such as thepositions described for inside antennas 312 of the 11-antenna RSSI-onlysystem for inside/outside vehicle microlocation (illustrated in FIG.23). In such an embodiment, antennas 312 positioned near each desiredzone (e.g., front driver seat, front passenger seat, rear driver seat,rear passenger seat, rear trunk/cargo area) may be used to determineproximity (or lack of proximity) to corresponding zones, as well asproximity (or lack of proximity) to corresponding doors (e.g., for usewith adjusting algorithm processing based upon door state, as describedherein). For example, the system 100 may determine that the portabledevice 110 is located in the driver seat zone 400FL, if (a) the insidefront driver antenna 312-2 RSSI is larger than all other applicableinside antennas 312 by a threshold, or (b) if the inside front driverantenna 312-2 RSSI is not larger than all other applicable insideantennas 312 by a threshold (e.g., said threshold is not satisfied), andno other applicable inside antenna 312 RSSI exceeds a threshold, and theinside front driver antenna 312-2 is greater than all other applicableantennas 312. Additionally, door state may be used to inform which doora portable device 110 may be located (e.g., if the driver door is open,and the portable device 110 may be proximate to the front driver antenna312-2 as determined by its RSSI exceeding a threshold [and/or becausemultiple applicable inside antennas exceed a threshold], the system 100may determine than the portable device 110 is proximate to the driverseat or door). Any combination of the above methods, including methodsthat provide confirmation by absence (i.e., not near a particularantenna 312), may be used to infer in which seat or near which door aportable device 110 is located. The set of antennas 312 to include insaid methods is not limited to inside antennas 312—outside antennas 312may also be used, for example, to provide additional confidence in theproximity to a particular zone and/or to provide additional confidencein the absence of proximity to a particular zone. It should also benoted that inside zone and/or door proximity may be determined usingangles and/or distance (time of flight) in addition to, or instead of,RSSI, as described herein.

Antenna 312 placement for inside seat and/or door determination may varydepending upon the application goals, available packaging locations, andsensor 310/antenna 312 packaging and operating capabilities. Forexample, higher antenna 312 placement locations, such as in theheadliner, near the top of the pillars, upper seat backs, or headrests,etc., may provide better performance than lower placement locations,such as in the middle of doors, in seats or lower seat backs, in themiddle of the pillars, consoles, or near the floor, etc., because higherpositions maintain a better RF path/line-of-sight to the portable device110 when a person is sitting in and holding and/or using the portabledevice 110 in the vehicle 500 and also because such positions minimizeobstructions caused by other peoples' bodies in the vehicle.

Any of the above and subsequent embodiments may be combined to determinewhich seat zone in which a portable device 110 is located. The seatingposition may be used to enable seat-specific infotainment, billing,targeted marketing, and so on.

E. Inside/Outside Vehicle Microlocation Embodiment

Use of the term vehicle 500 is considered to include any mobile machinewhich transports people or cargo, including but not limited to wagons,bicycles, motorcycles, automobiles, cars, trucks, trains, trams, ships,boats, aircraft, and spacecraft. For example, placement of antennasinside and outside of the vehicle, in orientations and in conjunctionwith the vehicle shell, to enable the detection of the presence ofdevices 110 located either inside, outside, near or far from, thevehicle using Bluetooth Low Energy. Additionally, zones may be createdto enable the detection of devices 110 in various zones outside thevehicle (e.g., driver door 142, passenger door 142, trunk, hood, reardriver door 142, rear passenger door 142, etc.).

As described in the Doorman and Sniffing disclosures (U.S. patentapplication Ser. No. 14/620,959, entitled SYSTEM AND METHOD FORCOMMUNICATING WITH A VEHICLE, filed Feb. 12, 2015, to Ellis et al., andU.S. Provisional Patent Application No. 62/323,262 entitled SYSTEM ANDMETHOD FOR ESTABLISHING REAL-TIME LOCATION, filed Apr. 15, 2016, toStitt et al.—the disclosures of which are incorporated herein in theirentirety), additional techniques may be used in addition to theRSSI-based differential approach to increase accuracy and precision(e.g., trilateration, triangulation, fingerprinting, AoA, etc.).

The inside/outside position can be used to authenticate identity andenable payment for automated taxi and car/ride sharing services, enableaccess to exterior and/or interior vehicle systems, automaticallylock/unlock doors 142 (as described in other systems), deliver targetedmarketing (interior or exterior of vehicle), and so on. An example ofthis configuration can be seen in the illustrated embodiment FIG. 20, inwhich the vehicle 500 includes first and second antennas 312A, 312Barranged on opposing sides of a physical boundary 411 between theinterior space 502 and the exterior space 504 defined by structure ofthe vehicle 500. In the illustrated embodiment, the antenna 312A isdisposed to detect a device 110 within at least one of a zone 400A and azone 401A nearer to the vehicle structure. Both zones 400A, 401A areoutside vehicle space 502. The antenna 312B may be disposed to detect adevice 110 within a zone 400B within the interior space 502. Based onone or more signal characteristics detected with respect to the antennas312A, 312B, the system 100 may determine a position of the device 110.In one example, a virtual boundary 410A-B defined by the antennas 312A,312B may facilitate identifying position information about the device110.

The following sections describe more specific embodiments ofmicrolocation with respect to a vehicle 500—although it should beunderstood, as discussed herein, that aspects of each of the followingembodiments may be utilized in connection with any other embodiment,including embodiments outside the realm of vehicles.

E.1 Inside/Outside Vehicle Microlocation Embodiment with RSSI

In one embodiment, RSSI may be used to determine position the device 110relative to the vehicle 500 (e.g., using a heuristic fingerprint,probabilistic heuristics, trilateration, multilateration, etc.). RSSIreadings are obtained using a sniffing approach, as described herein;however, the embodiments themselves need not utilize the use of aparticular architecture to obtain readings.

In one or more of the described embodiments, the system 100 may provide,for each reported zone 400, a correctness likelihood indicator (e.g., aconfidence score/metric, a likelihood score/metric, probability relativeto other reported zones 400 and/or the current zone 400, etc.).

E.1.a Three (3) Antenna RSSI-Only System

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 21, the system 100 may use RSSI and three (3) antennas312:

-   -   1. Near, on, or in Exterior Driver Door (e.g., mirror, trim,        wheel well, door handle, etc.). Antenna 312-1    -   2. Near, on, or in Interior Driver Door (e.g., door 142,        A-pillar, B-pillar, headliner, floor, etc.). Antenna 312-2    -   3. Near or at Center (e.g., center stack, arm rest, headliner,        floor, cup holder, cabin lights, dashboard, etc.). Antenna 312-3

In this system 100, the portable device 110 may communicate with amaster device 120 located on the interior 502 of the vehicle 500 that isseparate from the three (3) antennas identified above. In an alternateembodiment, the master device 120 may be located on the exterior 504 ofthe vehicle 500.

As depicted in the illustrated embodiment of FIG. 21, this system 100may be capable of determining at least the following zones 400: A)inside near driver seat, B) outside near driver door 142, C) not nearthe vehicle, but connected, and D) not connected.

Additional zones 400 may be defined, with varying levels of accuracy.For example, another outside zone 400 may be defined outside the driverdoor 142, that extends further away from the door 142 (an approachzone), but the ability of the system 100 to accurately determine whetheror not the device 110 is located within that zone 400 may be limited bythe underlying capabilities of the communications medium (e.g., BLE vs.UWB vs. LF).

Determining in which zone 400 the portable device 110 is located may beaccomplished by combining the differential and threshold techniques,along with the signal analysis techniques, described within thisdisclosure. The system 100 may distinguish zone A (inside) from otherzones by requiring both a differential between antenna 312-1 and antenna312-2 to indicate inside (e.g., [312-2]>[312-1]) and the maximum RSSI(or minimum computed distance) amongst a set of antennas (e.g., 312-2and 312-3) to be within a predetermined threshold (or threshold range).There exist alternate embodiments where only thresholds are evaluated,or only differentials are evaluated, but not in combination; using boththresholds and differentials (with the appropriate mix and placement ofantennas) may yield a better performing system that is able to bettermitigate many environmental and RF propagation/path-loss effects.

The system 100 may distinguish zone B from C by requiring that themaximum RSSI (or minimum computed distance) amongst a set of antennas(e.g., 312-2 and 312-3) to be within one or more predetermined thresholdranges (e.g., within a near threshold range, etc.).

The system 100 may determine the position of the portable device 110 tobe in zone C, if the portable device 110 is connected (i.e., iscommunicating with one or more master devices 120) and was notdetermined to be in zones A or B. The system 100 may also determine theposition of the portable device 110 to be in zone C, if the portabledevice 110 is connected and the maximum RSSI (or minimum computeddistance) amongst a set of antennas (e.g., 312-2 and 312-3) are beyondone or more predetermined threshold ranges (e.g., further than a farthreshold range, above a minimum RSSI, etc.).

The system 100 may determine the position of the portable device 110 tobe in zone D, if the portable device 110 is not connected.

In addition to, or in place of, a single threshold (or threshold range),different mixes of antennas 312 may have different thresholds and/orcombinations of thresholds, to better handle system edge cases (e.g.,the max RSSI of antennas 312-2 and 312-3 must be less than X, the RSSIof antenna 312-1 must be less than Y, etc.).

Antenna measurement/approximation error may be expressed as part of thethreshold range, or as an additional range applied to each threshold (orthreshold range). For example, if the measurement/approximation error is2 dBm, thresholds (and threshold ranges) may be expressed as −50 dBm+/−2dBm, −52 dBm, or −48 dBm, −60 dBm to −30 dBm+/−2 dBm, −58 dBm to −28dBm, −58 dBm to −32 dBm, −62 dBm to −28 dBm, or −62 dBm to −32 dBm, andso on.

Differentials may also have a threshold or threshold range applied(e.g., to be considered inside, [312-2] must be greater than [312-1] byat least X).

Hysteresis (time- or value-based) may also be applied to a differentialor threshold (or threshold range), requiring one value (or amount oftime in) to enter a zone (e.g., transition from A to B) and anothervalue (or amount of time out) to exit a zone (e.g., transition from B toA). Hysteresis may also be a means to encapsulate measurement error.Hysteresis may also be applied to zone transition decisions themselves(e.g., requiring that multiple positioning iterations result in the samedecision before announcing said decision).

Thresholds and threshold ranges may be expressed and evaluated in termsof RSSI (e.g., dB, dBm, etc.), computed distance (e.g., meters),synthetic values (i.e., another value derived at least in part fromRSSI), or any combination thereof.

Distances computed from different collections and aggregation methods(min, max, average, cluster, median, etc.) may use different sets ofequations or approaches. For example, distances computed from individualantennas may use equation or approach X, whereas the distance computedfrom the max of antennas 312-2 and 312-3 may use equation or approach Y.

The system may distinguish zone B from C by requiring that the maximumRSSI (or minimum computed distance) amongst a set of antennas (e.g.,312-2 and 312-3) to be within a predetermined threshold range (e.g.,within a near driver door threshold range). In addition to, or in placeof, a single threshold, different mixes of antennas may have differentthresholds, and combinations of thresholds, to better handle system edgecases (e.g., the max RSSI of antennas 312-2 and 312-3 must be within anear driver door threshold range, the RSSI of antenna 312-1 must be lessthan X, the RSSI of antenna 312-1 must be less than Y and the max RSSIof antennas 312-2 and 312-3 must be within a Y . . . Z, etc.).

A BLE-based version of this embodiment may have several possibledisadvantages. In particular, this embodiment in one configuration maynot work optimally or in compliance with one or more criteria when theportable device 110 is not located near the driver side of the vehicle500, as the system 100 may not always able to distinguish between insidein the driver seat 510 versus outside on the passenger side. BLE is alsoa noisy communications medium, as described in subsequent embodiments,and as such, using fewer antennas 312 may result in lower accuracyand/or zone determination stability.

While this embodiment is described in the context of the driver side,and in particular the driver side front door/seat, this approach is notso limited and is applicable to other vehicle sides, doors 142, andseats.

The system 100 may, alternately or additionally, determine the zone 400in which the portable device 110 is located using a trilateration-and/or multilateration-based approach (described herein).

The system 100 may, alternately or additionally, determine distanceusing a time-of-flight-/time-of-arrival-(TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.1.b Seven (7) Antenna RSSI-Only System

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 22, the system 100 may use RSSI and seven (7) antennas312:

-   -   1. Near, on, or in Exterior Driver Door (e.g., mirror, trim,        wheel well, door handle, B-pillar, etc.). Antenna 312-1    -   2. Near, on, or in Interior Driver Door (e.g., door 142,        A-pillar, B-pillar, headliner, floor, etc.). Antenna 312-2    -   3. Near or at Center (e.g., center stack, arm rest, headliner,        floor, cup holder, cabin lights, dashboard, etc.). Antenna 312-3    -   4. Near, on, or in Exterior Passenger Door (e.g., mirror, trim,        wheel well, door handle, B-pillar, etc.). Antenna 312-4    -   5. Near, on, or in Interior Passenger Door (e.g., door 142,        A-pillar, B-pillar, headliner, floor, etc.). Antenna 312-5    -   6. Near, on, or in Exterior Rear Tailgate/Trunk (e.g., trim,        spare tire well, door handle, bumper/fascia, etc.). Antenna        312-6    -   7. Near, on, or in Interior Rear Tailgate/Trunk (e.g., trim,        spare tire well, door handle, bumper, etc.). Antenna 312-7

In this system 100, the portable device 110 may communicate with amaster device 120 located on the interior 502 of the vehicle 500 that isseparate from the seven (7) antennas 312 identified above. In analternate embodiment, the master device 120 may be located on theexterior 504 of the vehicle 500. In an alternative embodiment, there isa five (5) antenna configuration that omits the tailgate/trunk antennas312-6, 316-7.

As depicted in the illustrated embodiment of FIG. 22, this system 100may be capable of determining at least the following zones: A) inside,B) outside near driver side, C) outside near passenger side, D) outsidenear tailgate/trunk, E) not near the vehicle, but connected, and F) notconnected.

Additional zones 400 may be defined, with varying levels of accuracy.For example, another outside zone 400 may be defined outside of the nearzones 400, that extends further away from the vehicle 500 (e.g., anapproach zone). The system 100 may also be able to determine positionwithin the vehicle 500—near the driver side, passenger side, or trunk.The ability of the system 100 to accurately determine whether or not thedevice 110 is located within what zone 400 may be limited by theunderlying capabilities of the communications medium (e.g., BLE vs. UWBvs. LF).

Similar to the three (3) antenna system described in connection withFIG. 21, the system 100 in the illustrated embodiment of FIG. 22 maydetermine the zone 400 in which the portable device 110 is located bycombining the differential and threshold techniques described withinthis disclosure. The system 100 may distinguish zone A (inside) fromother zones 400 by requiring both a differential between the maximum ofthe inside antennas (312-2, 312-3, 312-5, and 312-7) and the maximum ofthe outside antennas (312-1, 312-4, and 312-6) to indicate inside (e.g.,inside>outside) and the maximum RSSI (or minimum computed distance)amongst a set of antennas (e.g., 312-2, 312-3, 312-5, and 312-7) to bewithin a predetermined threshold (or threshold range). In addition to,or alternative to, using a differential between the maximum inside andoutside antennas 312, the system 100 may distinguish zone A (inside)from other zones 400 by requiring the differential between certain pairsof antennas 312 (e.g., antennas 312 that generate a virtual boundary 410of interest) to provide an appropriate indication. For example, thesystem 100 may utilize the differential between antennas 312-1 and312-2, antennas 312-4 and 312-5, and antennas 312-6 and 312-7, to allindicate inside to be located in zone A. Which set of differentials touse may be selected based upon the values of other differentials andthresholds that are satisfied (or not); for example, if all of thedifferentials indicate inside, and the maximum RSSI threshold is withinan alternate range of the primary threshold (e.g., just outside theprimary threshold range, but within a secondary threshold range), thenthe system 100 may locate the portable device in zone A, regardless ofthe primary threshold not being satisfied.

The system 100 may distinguish zones B, C, or D from E by requiring thatthe maximum RSSI (or minimum computed distance) amongst a set ofantennas (e.g., 312-2, 312-3, 312-5, and 312-7) to be within one or morepredetermined threshold ranges (e.g., within a near driver thresholdrange, within a near passenger threshold range, within a near tailgatethreshold range, etc.).

The system 100 may determine the position of the portable device 110 tobe in zone E, if the portable device 110 is connected (i.e., iscommunicating with one or more master devices 120) and was notdetermined to be in zones A-D. The system 100 may also determine theposition of the portable device 110 to be in zone E, if the portabledevice 110 is connected and the maximum RSSI (or minimum computeddistance) amongst a set of antennas (e.g., 312-2, 312-3, 312-5, and312-7) are beyond one or more predetermined threshold ranges (e.g.,further than a far threshold range, above a minimum RSSI, etc.).

The system 100 may determine the position of the portable device 110 tobe in zone F, if the portable device 110 is not connected.

Similar to the three (3) sensor system 100, in addition to, or in placeof, a single threshold, different mixes of antennas 312 may havedifferent thresholds, and combinations of thresholds, to focus onhandling system edge cases (e.g., the max RSSI of antennas 312-2, 312-3,312-5, and 312-7 must be within a near driver threshold range, the RSSIof antenna 312-1 must be less than X, the RSSI of antenna 312-1 must beless than Y and the max RSSI of antennas 312-2, 312-3, 312-5, and 312-7must be within a Y . . . Z, etc.).

Antenna measurement/approximation error may be expressed as part of thethreshold range, or as an additional range applied to each threshold (orthreshold range). For example, if the measurement/approximation error is2 dBm, thresholds (and threshold ranges) may be expressed as −50 dBm+/−2dBm, −52 dBm, or −48 dBm, −60 dBm to −30 dBm+/−2 dBm, −58 dBm to −28dBm, −58 dBm to −32 dBm, −62 dBm to −28 dBm, or −62 dBm to −32 dBm, andso on.

Differentials may also have a threshold or threshold range applied(e.g., to be considered inside, [312-2] must be greater than [312-1] byat least X).

Hysteresis (time- or value-based) may also be applied to a differentialor threshold (or threshold range), requiring one value (or amount oftime in) to enter a zone (e.g., transition from A to B) and anothervalue (or amount of time out) to exit a zone (e.g., transition from B toA). Hysteresis may also be a means to encapsulate measurement error.Hysteresis may also be applied to zone transition decisions themselves(e.g., requiring that multiple positioning iterations result in the samedecision before announcing said decision).

Thresholds and threshold ranges may be expressed and evaluated in termsof RSSI (e.g., dB, dBm, etc.), computed distance (e.g., meters),synthetic values (i.e., another value derived at least in part fromRSSI), or any combination thereof.

Distances computed from different collections and aggregation methods(e.g., min, max, average, cluster, median, etc.) may use different setsof equations or approaches. For example, distances computed fromindividual antennas 312 may use equation or approach X, whereas thedistance computed from the max of antennas 312-2, 312-3, 312-5, and312-7 may use equation or approach Y. As a further example, the driveroutside antenna (312-1), passenger outside antenna (312-4), and rearoutside antenna (312-6) may each have different equations or approachesfor computing distance.

The system 100 may distinguish between zones B, C, and D by determining,amongst the set of potential zone thresholds that are satisfied, whichzone's representative external antennas (e.g., 312-1 for B, 312-4 for C,312-6 for D) have the highest RSSI (or lowest computed distance).

In a BLE-based system, to enhance handling scenarios where a portabledevice 110 is located in a person's pocket (i.e., attenuated by theirbody), multiple sets of antennas 312 and thresholds may be utilized todetermine whether the portable device 110 is or isn't in a near zone(where it may otherwise be determined as not near). Such processing mayutilize the system 110 to determine which near zone (B, C, or D) may beselected, regardless of whether the system 100 believes the portabledevice 110 is within the corresponding (or any) near zone thresholds. Ifprimary threshold ranges used to determine whether or not a portabledevice 110 is in a particular near zone 400 are not satisfied, but arewithin a secondary threshold range, and one or more other differentialsand/or secondary thresholds (using the same or other antennas 312) aresatisfied for a particular near zone 400, the system 100 may select thatnear zone 400. For example, if the system 100 believes the portabledevice 110 is on the driver side as determined using the representativeexternal antennas 312, but the maximum RSSI (or minimum computeddistance) amongst the set of antennas used to compute distance from thevehicle (e.g., 312-2, 312-3, 312-5, and 312-7) is not within the primarydriver side near threshold, but it is within a secondary driver sidenear threshold, and the driver side representative external antennas'312 RSSI (or computed distance, etc.) are within a corresponding nearoverride threshold, the system 100 may determine that the portabledevice 110 is located in zone B (driver near), as opposed to zone E (notnear). Such a determination may also incorporate the differentials ofvarious sensor pairs 312 to provide more confidence (e.g., ensure thatthe driver side antennas 312 indicate outside and that the passengerside antennas 312 indicate inside). Such a determination may alsoincorporate RSSIs (or computed distance, etc.) from other antennas 312to provide further confidence (e.g., if near the driver side, thepassenger side distance should be within a particular threshold range).

With some underlying communications technologies, RSSI may be quitenoisy due to signal blockers and reflectors, such as with BLE, anddespite the advanced signal analysis techniques identified in thisdisclosure, additional (intelligent) filtering may be implemented toprevent potentially unwanted transient zone transitions due to suchnoise or environment effects between near zones (B, C, and D). Suchfiltering may utilize a larger threshold difference to transition fromone near zone 400 to another (e.g., utilize a 5 dB RSSI differencebetween representative external antennas to transition from D to B or C,utilize a 10 dB RSSI difference between representative external antennas312 to transition from B to C, etc.). Such filtering may also includerequiring one or more differentials between certain pairs of antennas312 (e.g., antennas 312 that generate a virtual boundary 410 ofinterest) to provide an appropriate indication when transitioning into anear zone 400 and/or from one near zone 400 to another. For example, thesystem 100 may utilize the differential between 312-1 and 312-2 toindicate outside to transition from E to B, but may utilize thedifferential between 312-1 and 312-2 to indicate outside and thedifferential between 312-4 and 312-5 to indicate inside to transitionfrom C to B. In another example, the system may only utilize thedifferential between 312-1 and 312-2 to indicate outside and thedifferential between 312-4 and 312-5 to indicate inside whentransitioning from C to B when a threshold is not satisfied. In anotherexample, the system 100 may utilize the differential between 312-1 and312-2 and between 312-4 and 312-5 to indicate inside to transition to Dfrom B or C. These techniques may also be applied to other zonetransitions, including inside/outside.

Variance (or noise) in measured RSSI due to reflections, despite itspossible disadvantages, may provide a benefit: in systems 100 thatoperate across multiple frequencies/channels (e.g., BLE), it may bepossible to determine that a reflective object (e.g., another vehicle)is nearby through analysis of per-frequency/channel RSSI measurements(as described in Section C.9. For example, if a portable device is faraway, there may be variation amongst RSSI measurements across the vastmajority of channels; however, if a portable device 110 is nearby, theremay be substantial agreement amongst RSSI measurements across the vastmajority of channels; therefore, in situations where RSSI measurementson only a few channels vary significantly from the others (as determinedby one or more thresholds, which may encapsulatemeasurement/approximation error [described herein]), the system 100 mayconclude that a vehicle or other object is near that antenna 312 andadjust thresholds or methods, as appropriate. For example, the system100 may determine that another vehicle is present near the driver sideof the vehicle, and alter the thresholds or distance measurement methodsused with antennas 312 on that side of the vehicle 500, zonedetermination criteria, calibration/offsets, any other attribute ormethod disclosed herein, or any combination thereof. At a minimum, asdescribed previously, said invalid measurements may be filtered.

The system 100 may adjust thresholds, hysteresis, antenna 312combinations, differentials, combination methods, and/or any otherdisclosed method, based upon determined background power and/orbackground noise. For example, if the background power/noise determinedto be high, thresholds may be increased.

The system 100 may also adjust thresholds, hysteresis, antenna 312combinations, differentials, combination methods, and/or any otherdisclosed method, based upon RSSI measured from transmissions from thesystem's own antennas 312 (including the master device's 120 one or moreantennas 312). For example, if each antenna 312 measures the RSSI ofsignals transmitted by the master device 120, and said measured RSSI isabove a threshold (e.g., a predetermined [normal or open field]baseline, etc.), thresholds may be increased. For example, if oneantenna 312 measures the RSSI of signals transmitted by another antenna312, and said measured RSSI is above a threshold (e.g., a predetermined[normal or open field] baseline, etc.), the system 100 may determinethat a large reflective objective is nearby, or conversely, if themeasured RSSI is below a threshold, that an object exists between saidantennas 312.

In one embodiment, the system 100, when it has determined that a vehicleor object is nearby, such as by observing variance on only a fewchannels, or by measuring RSSI between antennas 312, as described above,the distance to said vehicle or object may computed using the differencebetween the measured RSSI and a predetermined [normal or open field]baseline, by using trilateration and/or multilateration, or any othermethod described herein, or any combination thereof.

Some antennas 312 may be placed in locations that are movable (such as adoor 142 or tailgate). In some cases, movement of the antennas 312 doesnot affect system operation. In other cases, knowledge of the equipment(vehicle) state may provide a means for the system 100 to alter whichthresholds, differentials, distance calculation methods, or othercomputations are performed. In some of those cases, the desired behaviormay be the same behavior as though the equipment state had not changed(e.g., when a portable device 110 is placed in the breach of an opendoor 142, it may be desirable for the system 100 to not indicate thatsaid portable device 110 is inside [zone A] and instead indicate outside[zone B, C, or D, as appropriate]). By using equipment state provided bythe vehicle 500, such alterations are possible. By receiving the door142 ajar status for each door 142, the system 100 may discard, or usealternate heuristics, for heuristics that incorporate that door'sdifferentials or antennas 312. For example, if the driver door 142 isopen, the corresponding inside antenna 312 may be omitted from the setof antennas 312 used to compute vehicle distance. For example, when theportable device 110 is located at the rear driver door 142 on theoutside of the vehicle cabin, if the driver front door 142 is closed,the differential may indicate outside, but if the driver door 142 isopen, the differential may indicate inside, calling for the use of anadditional threshold or comparison of additional differentials tocontinue to determine the portable device is positioned outside. Byreceiving the window state for each door 142, alternate signal analysismay be performed or different thresholds may be selected for affectedantennas 312. For example, if the vehicle glass is coated with anRF-blocking material, window up or down may significantly alter distancecalculations, whereas if it is not, the impact may be minor ornegligible.

The system 100 may, alternately or additionally, determine the zone 400in which the portable device 110 is located using a trilateration-and/or multilateration-based approach (described herein).

The system 100 may, alternately or additionally, determine distanceusing a time-of-flight-/time-of-arrival-(TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.1.c Eleven (11) Antenna RSSI-Only System

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 23, the system 100 may use RSSI, eleven (11) antennas:

-   -   1. Near, on, or in Exterior Front Driver Door (e.g., mirror,        trim, wheel well, door handle, B-pillar, etc.). Antenna 312-1    -   2. Near, on, or in Interior Front Driver Door (e.g., door 142,        A-pillar, B-pillar, headliner, floor, etc.). Antenna 312-2    -   3. Near or at Center (e.g., center stack, arm rest, headliner,        floor, cup holder, cabin lights, dashboard, etc.). Antenna 312-3    -   4. Near, on, or in Exterior Front Passenger Door (e.g., mirror,        trim, wheel well, door handle, B-pillar, etc.). Antenna 312-4    -   5. Near, on, or in Interior Front Passenger Door (e.g., door        142, A-pillar, B-pillar, headliner, floor, etc.). Antenna 312-5    -   6. Near, on, or in Exterior Rear Tailgate/Trunk (e.g., trim,        spare tire well, door handle, bumper/fascia, etc.). Antenna        312-6    -   7. Near, on, or in Interior Rear Tailgate/Trunk (e.g., trim,        spare tire well, door handle, bumper, etc.). Antenna 312-7    -   8. Near, on, or in Exterior Rear Driver Door (e.g., trim, wheel        well, door handle, etc.). Antenna 312-8    -   9. Near, on, or in Interior Rear Driver Door (e.g., door 142,        B-pillar, C-pillar, headliner, floor, etc.). Antenna 312-9    -   10. Near, on, or in Exterior Rear Passenger Door (e.g., trim,        wheel well, door handle, etc.). Antenna 312-10    -   11. Near, on, or in Interior Rear Passenger Door (e.g., door        142, B-pillar, C-pillar, headliner, floor, etc.). Antenna 312-11

In this system 100, the portable device 110 communicates with a masterdevice 120 located on the interior of the vehicle 500 that is separatefrom the eleven (11) antennas identified above. As shown in theillustrated embodiment of FIG. 23, this system 100 may be capable ofdetermining at least the following zones: A) inside, B) outside neardriver side, C) outside near passenger side, D) outside neartailgate/trunk, E) not near the vehicle 500, but connected, and F) notconnected.

Additional zones 400 may be defined, with varying levels of accuracy.For example, another outside zone 400 may be defined outside of the nearzones 400, that extends further away from the vehicle 500 (an approachzone 400). The system 100 may also be able to determine position withinor outside the vehicle 500—near the driver front door 142, driver reardoor 142, passenger front door 142, passenger rear door 142, or trunk.The ability of the system 100 to accurately determine whether or not thedevice is located within what zone 400 may be limited by the underlyingcapabilities of the communications medium (e.g., BLE vs. UWB vs. LF).

The eleven (11) antenna system 100 provides a possible advantage overthe seven (7) antenna system 100, in that it is able to more accuratelydetermine proximity and differentials relative to each door 142, and atmore points over the body of the vehicle 500, providing more robustinside/outside coverage around the shell of the vehicle 500. In aBLE-based system 100, the additional antennas 312 also make this system100 able to more accurately determine distance from the vehicle 500 indiverse environments. In a BLE-based system 100, the additional antennas312 also enable the system 100 to overcome some of the challenges othersystems have when positioning portable devices that may be inside aperson's pocket (front or back).

Similar to the seven (7) antenna system 100, determining in which zone400 the portable device 110 is located may be accomplished by combiningthe differential and threshold techniques described within thisdisclosure. The system 100 may distinguish zone A (inside) from otherzones 400 by requiring both a differential between the maximum of theinside antennas 312 (312-2, 312-3, 312-5, 312-7, 312-9, and 312-11) andthe maximum of the outside antennas 312 (312-1, 312-4, 312-6, 312-8, and312-10) to indicate inside (e.g., inside>outside) and the maximum RSSI(or minimum computed distance) amongst a set of antennas 312 (e.g.,312-2, 312-3, 312-5, 312-7, 312-9, and 312-11) to be within apredetermined threshold (or threshold range). In addition to, oralternative to, using a differential between the maximum inside andoutside antennas 312, the system 100 may distinguish zone A (inside)from other zones 400 by requiring the differential between certain pairsof antennas 312 (e.g., antennas 312 that generate a virtual boundary 410of interest) to provide an appropriate indication. For example, thesystem 100 may utilize the differential between antennas 312-1 and312-2, 312-4 and 312-5, 312-6 and 312-7, 312-8 and 312-9, and 312-10 and312-11, to all indicate inside to be located in zone A, oralternatively, may only utilize only one differential on each side ofthe vehicle 500 to indicate inside to be located in zone A. Which set ofdifferentials to use may be selected based upon the values of otherdifferentials and thresholds that are satisfied (or not); for example,if all of the differentials indicate inside, and the maximum RSSIthreshold is within an alternate range of the primary threshold (e.g.,just outside the primary threshold range, but within a secondarythreshold range), then the system 100 may locate the portable device inzone A, regardless of the primary threshold not being satisfied.

The system 100 may distinguish zones B, C, or D from E by requiring thatthe maximum RSSI (or minimum computed distance) amongst a set ofantennas 312 (e.g., 312-2, 312-3, 312-5, 312-7, 312-9, and 312-11) to bewithin one or more predetermined threshold ranges (e.g., within a neardriver threshold range, within a near passenger threshold range, withina near tailgate threshold range, etc.).

The system 100 may determine the position of the portable device 110 tobe in zone E, if the portable device 110 is connected (i.e., iscommunicating with one or more master devices) and was not determined tobe in zones A-D. The system 100 may also determine the position of theportable device 110 to be in zone E, if the portable device 110 isconnected and the maximum RSSI (or minimum computed distance) amongst aset of antennas 312 (e.g., 312-2, 312-3, 312-5, 312-7, 312-9, and312-11) are beyond one or more predetermined threshold ranges (e.g.,further than a far threshold range, above a minimum RSSI, etc.).

The system 100 may determine the position of the portable device 110 tobe in zone F, if the portable device 110 is not connected.

Similar to the seven (7) sensor system 100, in addition to, or in placeof, a single threshold, different mixes of antennas 312 may havedifferent thresholds, and combinations of thresholds, to better handlesystem edge cases (e.g., the max RSSI of antennas 312-2, 312-3, 312-5,312-7, 312-9, and 312-11 must be within a near driver threshold range,the max RSSI of antenna 312-1 and 312-8 must be less than X, the maxRSSI of antenna 312-1 and 312-2 must be less than Y and the max RSSI ofantennas 312-2, 312-3, 312-5, 312-7, 312-9, and 312-11 must be within aY . . . Z, etc.).

Antenna measurement/approximation error may be expressed as part of thethreshold range, or as an additional range applied to each threshold (orthreshold range). For example, if the measurement/approximation error is2 dBm, thresholds (and threshold ranges) may be expressed as −50 dBm+/−2dBm, −52 dBm, or −48 dBm, −60 dBm to −30 dBm+/−2 dBm, −58 dBm to −28dBm, −58 dBm to −32 dBm, −62 dBm to −28 dBm, or −62 dBm to −32 dBm, andso on.

Differentials may also have a threshold or threshold range applied(e.g., to be considered inside, [312-2] must be greater than [312-1] byat least X).

Hysteresis (time- or value-based) may also be applied to a differentialor threshold (or threshold range), requiring one value (or amount oftime in) to enter a zone 400 (e.g., transition from A to B) and anothervalue (or amount of time out) to exit a zone 400 (e.g., transition fromB to A). Hysteresis may also be a means to encapsulate measurementerror. Hysteresis may also be applied to zone transition decisionsthemselves (e.g., requiring that multiple positioning iterations resultin the same decision before announcing said decision).

Thresholds and threshold ranges may be expressed and evaluated in termsof RSSI (e.g., dB, dBm, etc.), computed distance (e.g., meters),synthetic values (i.e., another value derived at least in part fromRSSI), or any combination thereof.

Distances computed from different collections and aggregation methods(e.g., min, max, average, cluster, median, etc.) may use different setsof equations or approaches. For example, distances computed fromindividual antennas 312 may use equation or approach X, whereas thedistance computed from the max of antennas 312-2, 312-3, 312-5, 312-7,312-9, and 312-11 may use equation or approach Y. As a further example,the driver front outside antenna (312-1), driver rear outside antenna(312-8), and even the max of the driver outside antenna set (312-1 and312-8) may each have different equations or approaches for computingdistance; given multiple distance computations, the determined distancemay be selected using a predetermined or dynamic aggregation method(e.g., min, max, average, cluster, median, etc.) (e.g., the minimum ofthe driver side computed distances may be selected and used as thedriver side distance).

The system 100 may distinguish between zones B, C, and D by determining,amongst the set of potential zone thresholds that are satisfied, whichzone's representative external antennas 312 (e.g., 312-1 and 312-8 forB, 312-4 and 312-10 for C, 312-6 for D) have the highest RSSI (or lowestcomputed distance).

In a BLE-based system 100, to better handle scenarios where a portabledevice 110 is located in a person's pocket (i.e., attenuated by theirbody), multiple sets of antennas 312 and thresholds may be utilized todetermine whether the portable device 110 is or isn't in a near zone 400(where it may otherwise be determined as not near). Such processing mayutilize the system 100 to determine which near zone (B, C, or D) may beselected, regardless of whether the system 100 believes the portabledevice 110 is within the corresponding (or any) near zone thresholds. Ifprimary threshold ranges used to determine whether or not a portabledevice 110 is in a particular near zone 400 are not satisfied, but arewithin a secondary threshold range, and one or more other differentialsand/or secondary thresholds (using the same or other antennas 312) aresatisfied for a particular near zone 400, the system 100 may select thatnear zone 400. For example, if the system 100 believes the portabledevice 110 is on the driver side as determined using the representativeexternal antennas 312, but the maximum RSSI (or minimum computeddistance) amongst the set of antennas 312 used to compute distance fromthe vehicle 500 (e.g., 312-2, 312-3, 312-5, 312-7, 312-9, and 312-11) isnot within the primary driver side near threshold, but it is within asecondary driver side near threshold, and the driver side representativeexternal antennas' maximum RSSI (or minimum computed distance, etc.) arewithin a corresponding near override threshold, the system 100 maydetermine that the portable device 110 is located in zone B (drivernear), as opposed to zone E (not near). Such a determination may alsoincorporate the differentials of various antenna 312 pairs to providemore confidence (e.g., ensure that both, or at least one of, the driverside antennas 312 indicate outside and that both, or at least one of,the passenger side antennas 312 indicate inside). Such a determinationmay also incorporate the RSSIs (or computed distances, etc.) from otherantennas 312 to provide further confidence (e.g., if near the driverside, the passenger side distance may be within a particular thresholdrange).

With some underlying communications technologies, RSSI may be quitenoisy due to signal blockers and reflectors, such as with BLE, anddespite the advanced signal analysis techniques identified in thisdisclosure, additional (intelligent) filtering may be utilized toprevent unwanted transient zone transitions due to such noise orenvironment effects between near zones (B, C, and D). Such filtering mayinclude requiring a larger threshold difference to transition from onenear zone to another (e.g., utilize a 5 dB RSSI difference between themaximum of the representative external antennas 312 to transition from Dto B or C, utilize a 10 dB RSSI difference between the maximum of therepresentative external antennas 312 to transition from B to C, etc.).Such filtering may also include requiring one or more differentialsbetween certain pairs of antennas 312 (e.g., antennas 312 that generatea virtual boundary 410 of interest) to provide an appropriate indicationwhen transitioning into a near zone 400 and/or from one near zone 400 toanother. For example, the system 100 may utilize the differentialbetween 312-1 and 312-2 or 312-8 and 312-9 to indicate outside totransition from E to B, but may utilize the differential between 312-1and 312-2 and 312-8 and 312-9 to indicate outside and the differentialbetween 312-4 and 312-5 and 312-10 and 312-11 to indicate inside totransition from C to B. In another example, the system 100 may onlyutilize the differential between 312-1 and 312-2 or 312-8 and 312-9 toindicate outside and the differential between 312-4 and 312-5 or 312-10and 312-11 to indicate inside when transitioning from C to B when athreshold is not satisfied. In another example, the system 100 mayutilize the differential between 312-1 and 312-2 or 312-8 and 312-9 andbetween 312-4 and 312-5 or 312-10 and 312-11 to indicate inside totransition to D from B or C. These techniques may also be applied toother zone transitions, including inside/outside.

Variance (or noise) in measured RSSI due to reflections, despite itspossible disadvantages, may provide a benefit: in systems that operateacross multiple frequencies/channels (e.g., BLE), it may be possible todetermine that a reflective object (e.g., another vehicle 500) is nearbythrough analysis of per-frequency/channel RSSI measurements (asdescribed in Section C.9). For example, if a portable device 110 is faraway, there may be variation amongst RSSI measurements across the vastmajority of channels; however, if a portable device 110 is nearby, theremay be substantial agreement amongst RSSI measurements across the vastmajority of channels; therefore, in situations where RSSI measurementson only a few channels vary significantly from the others (as determinedby one or more thresholds, which may encapsulatemeasurement/approximation error [described herein]), the system 100 mayconclude that a vehicle 500 or other object is near that antenna 312 andadjust thresholds or methods, as appropriate. For example, the system100 may determine that another vehicle 500 is present near the driverside of the vehicle 500, and alter the thresholds or distancemeasurement methods used with antennas 312 on that side of the vehicle500, zone determination criteria, calibration/offsets, any otherattribute or method disclosed herein, or any combination thereof. At aminimum, as described previously, said invalid measurements may befiltered.

The system 100 may adjust thresholds, hysteresis, antenna 312combinations, differentials, combination methods, and/or any otherdisclosed method, based upon determined background power and/orbackground noise. For example, if the background power/noise determinedto be high, thresholds may be increased.

The system 100 may also adjust thresholds, hysteresis, antenna 312combinations, differentials, combination methods, and/or any otherdisclosed method, based upon RSSI measured from transmissions from thesystem's own antennas 312 (including the master device's one or moreantennas 312). For example, if each antenna 312 measures the RSSI ofsignals transmitted by the master device 120, and said measured RSSI isabove a threshold (e.g., a predetermined [normal or open field]baseline, etc.), thresholds may be increased. For example, if oneantenna 312 measures the RSSI of signals transmitted by another antenna312, and said measured RSSI is above a threshold (e.g., a predetermined[normal or open field] baseline, etc.), the system 100 may determinethat a large reflective objective is nearby, or conversely, if themeasured RSSI is below a threshold, that an object exists between saidantennas 312.

In one embodiment, the system 100, when it has determined that a vehicle500 or object is nearby, such as by observing variance on only a fewchannels, or by measuring RSSI between antennas 312, as described above,the distance to said vehicle 500 or object may computed using thedifference between the measured RSSI and a predetermined [normal or openfield] baseline, by using trilateration and/or multilateration, or anyother method described herein, or any combination thereof.

Some antennas 312 may be placed in locations that are movable (such adoor 142 or tailgate), or placed in locations affected by movable partsof the equipment (vehicle 500), as shown in the figure below. In somecases, movement of the antennas 312 or equipment components does notaffect system operation. In other cases, knowledge of the equipmentstate may provide a means for the system 100 to alter which thresholds,differentials, distance calculation methods, or other computations areperformed. In some of those cases, the desired behavior may be the samebehavior as though the equipment state had not changed (e.g., when aportable device 110 is placed in the breach of an open door 142, it maybe desirable for the system 100 to not indicate that said portabledevice 110 is inside [zone A] and instead indicate outside [zone B, C,or D, as appropriate]). The desired behavior may also be alternatebehavior, for example, if the rear tailgate is open, prevent anytransition to inside if the portable device 110 is believed to belocated near the tailgate. By using equipment state provided by thevehicle 500, such alterations are possible. By receiving the door ajarstatus for each door 142, the system 100 may discard, or use alternate,heuristics that incorporate that door's differentials or antennas 312.For example, if the driver door 142 is open, a corresponding insideantenna 312 may be omitted from the set of antennas 312 used to computevehicle distance. For example, when the portable device 110 is locatedat the rear driver door 142 on the outside of the vehicle cabin, if thedriver front door 142 is closed, a differential may indicate outside,but if the driver door 142 is open, a differential may indicate inside,requiring the use of an additional threshold or comparison of additionaldifferentials to continue to determine the portable device 110 ispositioned outside.

With antennas 312 in or near each door 142, and with door open stateproviding a clue to the potential proximity of the portable device 110,the system 100 may optimize or bias its decisions based upon relativelocation of the portable device 110 to each door 142. An example of suchan arrangement of antennas 312 is shown in the illustrated embodiment ofFIGS. 24-27, in which the doors 142 or windows may move leaving one ormore openings 143 to the interior space 502 of the vehicle 500.

By receiving the window state for each door 142, alternate signalanalysis may be performed or different thresholds may be selected foraffected antennas 312. For example, if the vehicle glass is coated withan RF-blocking material, window up or down may significantly alterdistance calculations, whereas if it is not, the impact may be minor ornegligible. For example, if the windows are closed and the doors 142 arenot open, this may adversely affect the ability of a portable device 110to transition from inside to outside, or outside to inside. Otherequipment states may also be incorporated, such as ignition status(which may also be used to substantially prevent or deter making certainzone transitions) and seat sensor status (if there is a body in a seat,it may provide additional data to help position a portable device 110).

The system 100 may, alternately or additionally, determine the zone 400in which the portable device 110 is located using a trilateration-and/or multilateration-based approach (described herein).

The system 100 may, alternately or additionally, determine distanceusing a time-of-flight-/time-of-arrival-(TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.1.d Other RSSI-Only Systems

Example embodiments of 3-, 5-, 7-, and 11-antenna systems have beendescribed. A system 100 may be implemented with more or less antennas312 while still using the identified methods. For example, a system 100with 12 antennas, an 11-antenna system with an additional antenna 312 inthe front of the vehicle 500, that additionally defines a front zone400. For example, a system 100 with 12 antennas, an 11-antenna systemwith an additional antenna 312 in the exterior rear of the vehicle 500,that provides assistance in defining the rear zone 400 (e.g., similar tothe driver/passenger side exterior antennas 312).

In the case of each embodiment, the system 100 may, alternately oradditionally, determine the zone 400 in which the portable device 110 islocated using a trilateration- and/or multilateration-based approach(described herein).

In the case of each embodiment, the system 100 may, alternately oradditionally, determine distance using atime-of-flight-/time-of-arrival- (TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.2 Inside/Outside Vehicle Microlocation Embodiment with Angle ofArrival

In these systems, angle of arrival is used to position the devicerelative to the vehicle 500 (e.g., using a heuristic fingerprint,probabilistic heuristics, multiangulation, etc.). Angle of arrivalreadings are obtained using the sniffing approach, as described herein;however, the embodiments themselves need not utilize a particulararchitecture to obtain readings. It is noted that angle of departure(AoD) may be used instead of angle of arrival (AoA), as well as any ofthe angle of arrival/departure methods described herein; however, thedisclosures below simply refer to all possible implementations where anangle is used (i.e., AoA and AoD may be used interchangeably, and anglemay refer to either methodology).

In one or more of these embodiments, the system 100 may provide, foreach reported zone 400, a correctness likelihood indicator (e.g., aconfidence score/metric, a likelihood score/metric, probability relativeto other reported zones 400 and/or the current zone 400, etc.).

It is noted that these disclosures refer to antennas 312, which, whenmeasuring the angle of a signal, as described herein in this disclosure,may actually be an antenna array. As described herein, any given sensor310 may be connected to multiple antennas 312 (or antenna arrays), andany given antenna 312 (or antenna array) may be connected to multiplesensors 310.

It is noted that, as described elsewhere, these antennas 312 may provideone or more angle measurements (e.g., horizontal, vertical, orhorizontal and vertical angle measurements, etc.). For example, anantenna 312 that reports a vertical angle may provide the system 100with the ability to estimate the vertical position (e.g., distance toground) of a portable device 110 relative to a vehicle 500. It isimportant to note that, although not discussed directly in the RSSI-onlydescriptions, because virtual boundaries may be defined in 3D space(e.g., using an RSSI differential with an appropriately placed groundplane or other divider [as described herein]), similar to the verticalangle approach described above, the system 100 may also use anRSSI-based differential across multiple antennas 312, with a separatingground plane/divider parallel to the ground, to determine low versushigh portable device 110 vertical position (or potentially more verticalpositions, with additional antennas 312 and ground planes/dividers).

The angle of arrival based systems described below rely only uponangles. It is noted that while such angle-only systems use only anglesto determine zones 400, they may also use RSSI to distinguish betweenrelevant and irrelevant signals (e.g., reflections, signals that are toofar away, etc.), whether using thresholds or other signal analysistechniques (e.g., significantly lower than other signals, etc.). Systemsthat additionally use the prior-described RSSI approaches to determinezones 400 are described herein (as AoA-RSSI systems).

E.2.a Twelve (12) Antenna AoA-Only System

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 48, the system 100 may use angle of arrival (AoA),twelve (12) antennas:

-   -   1. Near, on, or in exterior driver side front corner covering        driver side (e.g., driver side of driver side headlight        assembly, driver side of driver side front quarter panel trim,        front driver side wheel well, driver side of front        fascia/bumper, driver side mirror, etc.). Antenna 312-1    -   2. Near, on, or in exterior driver side front corner covering        front (e.g., front of driver side headlight assembly, front of        driver side quarter panel trim, front driver side of front        fascia/bumper, driver side of front grille, etc.). Antenna 312-2    -   3. Near, on, or in exterior passenger side front corner covering        front (e.g., front of passenger side headlight assembly, front        of passenger side quarter panel trim, front passenger side of        front fascia/bumper, passenger side of front grille, etc.).        Antenna 312-3    -   4. Near, on, or in exterior passenger side front corner covering        passenger side (e.g., passenger side of passenger side headlight        assembly, passenger side of passenger side front quarter panel        trim, front passenger side wheel well, passenger side of front        fascia/bumper, passenger side mirror, etc.). Antenna 312-4    -   5. Near, on, or in exterior passenger side rear corner covering        passenger side (e.g., passenger side of passenger side taillight        assembly, passenger side of passenger side rear quarter panel        trim, rear passenger side wheel well, passenger side of rear        fascia/bumper, passenger side rear door handle, passenger side        gas tank cover, etc.). Antenna 312-5    -   6. Near, on, or in exterior passenger side rear corner covering        rear (e.g., rear of passenger side taillight assembly, rear of        passenger side quarter panel trim, rear passenger side of rear        fascia/bumper, etc.). Antenna 312-6    -   7. Near, on, or in exterior driver side rear corner covering        rear (e.g., rear of driver side taillight assembly, rear of        driver side quarter panel trim, rear driver side of rear        fascia/bumper, etc.). Antenna 312-7    -   8. Near, on, or in exterior driver side rear corner covering        driver side (e.g., driver side of driver side taillight        assembly, driver side of driver side rear quarter panel trim,        rear driver side wheel well, driver side of rear fascia/bumper,        driver side rear door handle, driver side gas tank cover, etc.).        Antenna 312-8    -   9. Near, on, or in interior front center covering interior        (e.g., center of dashboard, center stack, am rest, cup holder,        rear-view mirror, center of headliner or roof-mounted        glasses-storage container near windshield, etc.). Antenna 312-9    -   10. Near, on, or in interior passenger side center covering        interior (e.g., passenger B-pillar, passenger C-pillar,        headliner near passenger B/C-pillar, floor near passenger        B/C-pillar, passenger front door 142, passenger rear door 142,        back/headrest of front/rear passenger seat, etc.). Antenna        312-10    -   11. Near, on, or in interior rear center covering interior        (e.g., center of headliner near tailgate/trunk or rear window,        center of floor near tailgate/trunk or rear window, spare tire        well, tailgate/trunk, bumper, etc.). Antenna 312-11    -   12. Near, on, or in interior driver side center covering        interior (e.g., driver B-pillar, driver C-pillar, headliner near        driver B/C-pillar, floor near driver B/C-pillar, driver front        door 142, driver rear door 142, back/headrest of front/rear        driver seat, etc.). Antenna 312-12

In this system 100, the portable device 110 communicates with a masterdevice 120 located on the interior of the vehicle 500 that is separatefrom the twelve (12) antennas 312 identified above.

In this system 100, as disclosed, it is assumed that the antennas 312are limited to a 180° field-of-view (e.g., because one side of theantenna 312 is intentionally blocked, to prevent signals from reachingthe antenna 312 from that side of the antenna 312 [i.e., the plane ofprinted circuit board opposite the plane on which the antenna array isplaced], or because the vehicle metal blocks the signal to a portion ofthe antenna 312, etc.); however, alternate embodiments exist whereinantennas 312 with a larger field-of-view (up to 360°) are used. It isnoted, that even though the field-of-view for front/rear and sideantennas 312 are shown as perpendicular to one another (which may beideal) in the illustrated embodiment of FIG. 48 packaging locationsand/or actual antenna field-of-view may result in the field-of-view forvarious antennas 312 being at slight angles relative to one another,resulting in either gaps or overlaps.

Horizontal angle measurements are primarily described in this and othersystem 100 disclosures; however, it is understood that, as previouslydescribed, the system 100 (and alternate and/or derived systemembodiments) may use either, or both, horizontal and vertical anglemeasurements (and possibly other angle measurements, such as multiplemeasurements of each, or measurements on yet another axis).

In this embodiment, as described above, the exterior antennas 312 arelocated in or near each of the headlights/taillights, as shown in thefollowing figure. There is an alternate embodiment, where antennas 312are located near the exterior side centers of the vehicle 500 (i.e.,grille, driver B-pillar, passenger B-pillar). There are also embodimentswhere antennas 312 are located in any position between these embodiments(e.g., due to packaging requirements imposed by a particular vehicle500).

In this embodiment, as described above, the interior antennas 312 arelocated near the center of each interior side of the vehicle 500 (i.e.,driver side, front, passenger side, rear), as shown in the followingfigure. There is an alternate embodiment, where antennas 312 are locatednear the interior corners of the vehicle 500 (i.e., driver side front,passenger side front, passenger side rear, driver side rear). There arealso embodiments where antennas 312 are located in any position betweenthese embodiments (e.g., due to packaging requirements imposed by aparticular vehicle 500).

This system 100 may be capable of determining at least the followingzones 400: A) inside, B) outside near driver side, C) outside nearpassenger side, D) outside near tailgate/trunk, E) outside near front,F) not near the vehicle 500, but connected, and G) not connected.

In addition to A, the system 100 may also determine one or more of thefollowing zones 400: A_(DF) (interior driver front), A_(PF) (interiorpassenger front), A_(DR) (interior driver rear), A_(DF) (interiorpassenger rear), A_(T) (interior trunk).

The above zones 400, along with the field of view 412 of each antenna312 and example thresholds that may be used to define each zone 400(with measurement/approximation error markers) are illustrated in theillustrated embodiment of FIG. 48.

Additional zones 400 may be defined, with varying levels of accuracy.For example, another outside zone 400 may be defined outside of the nearzones 400, that extends further away from the vehicle 500 (an approachzone 400). Vertical zones 400 may also be defined, also with varyinglevels of accuracy. For example, low, medium, and high vertical zones400 may be defined for near zones 400. The ability of the system 100 toaccurately determine whether or not the device is located within whatzone 400 may be limited by the underlying capabilities of thecommunications medium (e.g., BLE vs. UWB vs. LF) and accuracy of anglemeasurement facilities (e.g., measurement/approximation error).

Each antenna's angles and/or thresholds may be defined in anyorientation and/or unit; however, in this disclosure, angles andthresholds are expressed in degrees (e.g., versus radians). For example,in this disclosure, it is assumed that for all horizontal anglemeasurements, 0° (and 360°) is towards the front of the vehicle 500 and90° is towards the passenger side, and for all vertical anglemeasurements, 0° is parallel to the ground, +90° is towards the sky(i.e., up), and −90° is towards the ground (i.e., down). Alternatively,for example, for antenna 312-12, 0° may be towards the front of thevehicle 500 and 90° may be towards the passenger side, whereas forantenna 312-10, 90° may be towards the driver side. The orientation ofeach antenna 312 is assumed to be fixed (predetermined) relative to thevehicle 500. There exist alternate embodiments wherein antenna 312orientation is not fixed, such as when an antenna 312 is placed on amovable part of the vehicle 500, in which case, the antenna 312orientation may be determined dynamically.

The system 100 may distinguish zone A (inside) from other zones 400 byrequiring the angles measured from each interior antenna 312 (312-9through 312-12) to be within a predetermined threshold (or thresholdrange). The system 100 may additionally utilize, to determine zone A,that exterior antennas (312 through 312-8) be not receiving (or notconsistently receiving) signals (or valid signals [e.g., reflectedsignals may be deemed invalid, a measured angle may vary toosignificantly from prior measurements, etc.]) from the portable device110, be not measuring consistent angles (i.e., that if exterior antennas312 are measuring signals, that said measurements vary significantly[perhaps indicating that received measurements are due to reflections orfrom far away]), be within (or outside) a predetermined threshold (orthreshold range), or any combination thereof.

The system 100, when it has determined that the portable device 110 isin zone A (inside), may determine whether the portable device 110 islocated in zone A_(DF), A_(PF), A_(DR), A_(PR), or A_(T) by requiringthat angles measured from combinations of interior antennas (312-9through 312-12) be within predetermined thresholds (or thresholdranges). For example, it may be determined that the portable device 110is located in zone A_(DF), when antenna 312-9 measures the angle to bein range 180° to 270°, antenna 312-10 measures the angle to be within270° to 0°, antenna 312-11 measures the angle to be in range 180° to270°, and antenna 312-12 measures the angle to be in range 0° to 90°.The system 100 may alternatively determine zone A_(DF), given that itwas determined that the portable device 110 is in zone A, by using onlytwo antennas 312: antenna 312-9 or 312-11 along with antenna 312-10 or312-12; zones A_(PF), A_(DR), and A_(PR) may be determined in a similarmanner. For example, it may be determined that the portable device 110is located in zone A_(T), when antenna 312-9 measures the angle to be inrange 90° to 270°, antenna 312-10 measures the angle to be within 180°to 225°, antenna 312-11 measures the angle to be in range 90° to 270°,and antenna 312-12 measures the angle to be in range 135° to 180°. Thesystem 100 may alternatively determine zone A_(T), given that it wasdetermined that the portable device 110 is in zone A, by using onlyantennas 312-10 and 312-12. For example, with regard to zone A_(T)determination, additional confidence may be provided by furtherrestricting the threshold for antenna 312-9 (e.g., to utilize themeasured angle to be within 155° to 205°).

When a zone 400 may be computed with varying numbers of antennas 312(e.g., with varying levels of confidence), multiple thresholds may beutilized to determine which antennas 312 to use. For example, the system100 may normally determine A_(DF) using all four internal antennas 312(312-9 through 312-12), as described above, but may only utilize twointernal antennas 312 (as described above), when zone A is alreadydetermined, antenna 312-12 measures the angle to be in range 30° to 60°,and antenna 312-9 measures the angle to be in range 210° to 240°. Forexample, if the vertical position of a portable device 110 is determinedto be low, one set of antennas 312 and/or thresholds may be used, and ifthe vertical position is determined to be high, another set of antennas312 and/or thresholds may be used.

The system 100 may distinguish zones B-E from F by applying an approachsimilar to that as used to determine zones A, A_(DF), A_(PF), A_(DR),A_(PR), and/or A_(T). Zones B-E may be determined by requiring thatangles measured from combinations of exterior antennas (312-1 through312-8) be within predetermined thresholds (or threshold ranges). Forexample, it may be determined that the portable device 110 is located inzone B, when antenna 312-1 measures the angle to be in range 180° to210° and antenna 312-8 measures the angle to be within 330° to 0°.

The system 100 may additionally utilize, to determine a particular zoneB-E, that any combination of other exterior antennas (312-1 through312-8) be not receiving (or not consistently receiving) signals (orvalid signals [e.g., reflected signals may be deemed invalid, a measuredangle may vary too significantly from prior measurements, etc.]) fromthe portable device 110, be not measuring consistent angles (i.e., thatif exterior antennas 312 are measuring signals, that said measurementsvary significantly [perhaps indicating that received measurements aredue to reflections or from far away]), be within (or outside) apredetermined threshold (or threshold range), or any combinationthereof. For example, it may be determined that the portable device 110is located in zone B, when antenna 312-1 measures the angle to be inrange 180° to 210°, antenna 312-8 measures the angle to be within 330°to 0°, antenna 312-2 does not receive signals from the portable device110 or measures the angle to be in its field of view 412 in the front ofthe vehicle 500 (e.g., 315° to 45°, 0° to 90°, etc.), antenna 312-7 doesnot receive signals from the portable device 110 or measures the angleto be in its field of view 412 in the rear of the vehicle 500 (e.g.,230° to 95°, 180° to 90°, etc.), and other exterior antennas 312 do notreceive signals, or do not measure consistent angles, from the portabledevice 110. Such additional constraints may be utilized to determine aparticular zone 400, or may be used as a means to provide additionalconfidence.

The system 100 may additionally utilize, to determine a particular zoneB-E, any combination of interior antennas (312-9 through 312-12) be notreceiving (or not consistently receiving) signals (or valid signals[e.g., reflected signals may be deemed invalid, a measured angle mayvary too significantly from prior measurements, etc.]) from the portabledevice 110, be not measuring consistent angles (i.e., that if exteriorantennas 312 are measuring signals, that said measurements varysignificantly [perhaps indicating that received measurements are due toreflections or from far away]), be within (or outside) a predeterminedthreshold (or threshold range), or any combination thereof. For example,it may be determined that the portable device 110 is located in zone B,when antenna 312-1 measures the angle to be in range 180° to 210°,antenna 312-8 measures the angle to be within 330° to 0°, antenna 312-9measures the angle to be within 270° to 225°, antenna 312-10 measuresthe angle to be within 225° to 315°, antenna 312-11 measures the angleto be within 270° to 315°. Alternatively, the system 100 mayadditionally utilize antenna 312-12 to not be receiving signals, or tonot be measuring angles consistently, from the portable device 110.Alternatively, the system 100 may use only antenna 312-10 (ignoringantennas 312-9, 312-11, and 312-12). Such additional constraints may beutilized to determine a particular zone 400, or may be used as a meansto provide additional confidence.

Similar to interior zones 400, when a zone 400 may be computed withvarying numbers of antennas 312 (e.g., with varying levels ofconfidence), multiple thresholds may be utilized to determine whichantennas 312 to use. For example, the system 100 may determine B usingfour external antennas 312 (e.g., 312-1, 312-2, 312-7, and 312-8), asdescribed above, but may only utilize two antennas 312 (e.g., 312-1 and312-8), as described above, when antenna 312-1 measures the angle to bein range 180° to 200°, and antenna 312-8 measures the angle to be inrange 340° to 0°. Alternatively, the system 100 may determine B usingtwo antennas (312-1 and 312-8), when other antennas 312 do not receivesignals, or do not measure consistent angles, from the portable device110, and may utilize more antennas 312 (e.g., 312-1, 312-2, 312-7, and312-8) when signals are being received from antennas 312 other than312-1 and 312-8. Alternatively, the system 100 may determine B usingthree antennas 312 (312-1, 312-8, and 312-10), when other antennas 312do not receive signals, or do not measure consistent angles, from theportable device 110, and may utilize more antennas 312 (e.g., 312-1,312-8, 312-9, 312-10, and 312-11) when signals are being received fromexternal antennas 312 other than 312-1 and 312-8. For example, if thevertical position of a portable device 110 is determined to be low, oneset of antennas 312 and/or thresholds may be used, and if the verticalposition is determined to be high, another set of antennas 312 and/orthresholds may be used.

Examples above are provided relative to zone B; zones C-E may bedetermined in a similar manner. Absence from one zone 400 may provideconfidence in the determination of another zone 400 (e.g., absence fromzone C may provide additional confidence in the presence in zone B). Forexample, if the portable device 110 is not determined to be in zone A,then there is greater confidence that it is located in another zone 400.

Unlike RSSI-based systems, angle-only-based systems do not computedistance directly; instead, presence within zones 400 defined by largeror alternate thresholds may be used to determine the presence in zones400 defined further from zones B-E (e.g., approach and/or welcome zones400). Distance may be determined using any number of approaches once azone 400 has been determined, such as by estimating the distance fromthe centroid of a zone 400 to the center of a vehicle 500 (or any otherreference point), by estimating the distance from a particular edge of azone to the center of the vehicle 500, etc. Distance may also bedetermined by estimating the distance to the center of the vehicle 500(or any other reference point) from the computed position when using amultiangulation-based positioning approach (described herein).

The system 100 may determine the position of the portable device 110 tobe in zone F, if the portable device 110 is connected (i.e., iscommunicating with one or more master devices) and was not determined tobe in zones A-E. The system 100 may also determine the position of theportable device 110 to be in zone F, if any combination of antennas 312(e.g., all, all exterior, all interior, etc.) are not receiving (or arenot consistently receiving) signals (or valid signals [e.g., reflectedsignals may be deemed invalid, a measured angle may vary toosignificantly from prior measurements, etc.]) from the portable device110, are not measuring consistent angles (i.e., that if exteriorantennas 312 are measuring signals, that said measurements varysignificantly [perhaps indicating that received measurements are due toreflections or from far away]), are within (or outside) any defined zoneF thresholds (or threshold ranges), or any combination thereof.

The system 100 may determine the position of the portable device 110 tobe in zone G, if the portable device 110 is not connected.

In addition to, or in place of, a single threshold, different mixes ofantennas 312 may have different thresholds, and combinations ofthresholds, to better handle system edge cases (e.g., when determiningzone B, the thresholds used when using antennas 312-1 and 312-8 may bedifferent from the thresholds used when using antennas 312-1, 312-2,312-7, and 312-8, or 312-1, 312-8, and 312-10, etc.).

Each antenna 312 has a measurement (approximation) error that may beexpressed in degrees (i.e., the antenna 312 approximates the angle ofthe signal, which may vary from the actual angle by an approximationerror). In a typical angle of arrival system, measurement error may be10° or 20°. In a coarse angle of arrival system, such as an angle ofarrival antenna array is formed by using an RSSI-based differentialantenna pair, measurement error may be 45° or 90°. The antennameasurement/approximation error may be different for vertical andhorizontal measurements (and additional measurements).

Antenna measurement/approximation error may be expressed as part of thethreshold range, or as an additional range applied to each threshold (orthreshold range). For example, if the measurement/approximation error is10°, thresholds (and threshold ranges) may be expressed as 90°+/−10°,80°, or 100°, 10° to 170°+/−10°, 0° to 160°, 0° to 180°, 20° to 160°, or20° to 180°, and so on.

Hysteresis (time- or value-based) may also be applied to thresholds (orthreshold ranges), requiring one value (or amount of time in) to enter azone 400 (e.g., transition from A to B) and another value (or amount oftime out) to exit a zone 400 (e.g., transition from B to A). Hysteresismay also be a means to encapsulate measurement/approximation error.Hysteresis may also be applied to zone 400 transition decisionsthemselves (e.g., requiring that multiple positioning iterations resultin the same decision before announcing said decision).

With some underlying communications technologies, measured angles may bequite noisy due to signal blockers and reflectors, such as with BLE, anddespite the advanced signal analysis techniques identified in thisdisclosure, additional (intelligent) filtering may be utilized toprevent unwanted transient zone transitions due to such noise orenvironment effects. Due to such reflections, it may be problematic torely upon the absence of measurements from a particular antenna 312 aspart of a set of constraints to determine a particular zone 400. As aresult, and as described herein in this disclosure, invalid measurementsmay be ignored (e.g., reflected signals [as determined by comparing RSSIor other mechanisms/algorithms], too much variance from priormeasurements, etc.]), or antennas 312 that have inconsistentmeasurements may be ignored or treated similarly to those as notreceiving signals, to help mitigate such problems. Even with suchfiltering, such angle-only-based system (i.e., a system that does notuse RSSI differentials/thresholds/ and/or distances to determine zones400) are vulnerable to reflections.

Variance (or noise) in measured angles due to reflections, despite itspossible disadvantages, may provide a benefit: in systems that operateacross multiple frequencies/channels (e.g., BLE), it may be possible todetermine that a reflective object (e.g., another vehicle 500) is nearbythrough analysis of per-frequency/channel angle measurements (asdescribed in Section C.9). For example, if a portable device 110 is notwithin the field of view 412 of the antenna 312, or far away, there maybe variation amongst angle measurements across the vast majority ofchannels; however, if a portable device 110 is within the field of view412 of the antenna 312, and nearby, there may be substantial agreementamongst angle measurements across the vast majority of channels;therefore, in situations where angle measurements on only a few channelsvary significantly from the others (as determined by one or morethresholds, which may encapsulate measurement/approximation error[described herein]), the system 100 may conclude that a vehicle 500 orother object is near that antenna 312 and adjust thresholds or methods,as appropriate. For example, the system 100 may determine that anothervehicle 500 is present near the driver side of the vehicle 500, andalter the thresholds or distance measurement methods used with antennas312 on that side of the vehicle 500, zone determination criteria,calibration/offsets, any other attribute or method disclosed herein, orany combination thereof. At a minimum, as described previously, saidinvalid measurements may be filtered.

The system 100 may adjust thresholds, hysteresis, antenna 312combinations, differentials, combination methods, and/or any otherdisclosed method, based upon determined background power and/orbackground noise. For example, if the background power/noise determinedto be high, thresholds may be tightened or relaxed.

The system 100 may also adjust thresholds, hysteresis, antenna 312combinations, differentials, combination methods, and/or any otherdisclosed method, based upon angles measured from transmissions from thesystem's own antennas 312 (including the master device's one or moreantennas 312). For example, if each antenna 312 measures the angle ofsignals transmitted by the master device 120, and said measured angle iswithin or outside a threshold range (e.g., a predetermined [normal oropen field] baseline, etc.), thresholds may be tightened or relaxed (orbe determined unusable). For example, if one antenna 312 measures theangle of signals transmitted by another antenna 312, and said measuredangle is within or outside a threshold range (e.g., a predetermined[normal or open field] baseline, etc.), the system 100 may determinethat a large reflective objective is nearby.

In one embodiment, the system 100, when it has determined that a vehicle500 or object is nearby, such as by observing variance on only a fewchannels, as described above, the distance to said vehicle 500 or objectmay computed using multiangulation (e.g., triangulation).

Some antennas 312 may be placed in locations that are movable (such asmoveable headlights, taillights, doors 142, tailgates/trunks, etc.), orplaced in locations affected by movable parts of the equipment (vehicle500), as shown in the figure below. In some cases, movement of theantennas 312 or equipment components does not affect system operation.In other cases, knowledge of the equipment state may provide a means forthe system 100 to alter which thresholds or other computations areperformed. In some of those cases, the desired behavior may be the samebehavior as though the equipment state had not changed (e.g., when aportable device 110 is placed in the breach of an open door 142, it maybe desirable for the system 100 to not indicate that said portabledevice 110 is inside [zone A] and instead indicate outside [zone B-E, asappropriate]). The desired behavior may also be alternate behavior, forexample, if the rear tailgate is open, preventing any transition toinside if the portable device 110 is believed to be located near thetailgate. By using equipment state provided by the vehicle 500, suchalterations are possible. By receiving the door ajar status for eachdoor 142 on which antennas 312 are placed, the system 100 may discard,or use alternate heuristics or thresholds, when said antennas 312 areutilized. For example, when the portable device 110 is located at therear driver door 142 on the outside of the vehicle cabin, if an antenna312 is located on the driver front door 142, and the driver front door142 is closed, that antenna 312 may indicate outside, but if the driverdoor 142 is open, an antenna 312 may indicate inside, requiring the useof an additional threshold or comparison of additional or alternatethresholds and antennas 312 to continue to determine the portable device110 is positioned outside. In an alternate example, when the portabledevice 110 is located at the rear driver door 142 on the outside of thevehicle cabin, if an antenna 312 is located on a non-moving part of theequipment, and the driver front door 142 is closed, that antenna 312 mayindicate outside, but if the driver door 142 is open, it may block thepath at certain angles (creating a gap), or provide a direct reflectionpath to another antenna 312, requiring the use of an additionalthreshold or comparison of additional or alternate thresholds andantennas 312 to continue to determine the portable device 110 ispositioned outside.

With door open state providing a clue to the potential proximity of theportable device 110, the system 100 may optimize or bias its decisionsbased upon relative location of the portable device 110 to each door142. By receiving the window state for each door 142, alternate signalanalysis may be performed or different heuristics used. For example, ifthe windows are closed and the doors 142 are not open, this mayadversely affect the ability of a portable device 110 to transition frominside to outside, or outside to inside. Other equipment states may alsobe incorporated, such as ignition status (which may also be used tosubstantially prevent or deter making certain zone transitions) and seatsensor status (if there is a body in a seat, it may provide additionaldata to help position a portable device 110). An example of such anarrangement of antennas 312 and states is depicted in the illustratedembodiment of FIGS. 28-31.

The system 100 may, alternately or additionally, determine the zone 400in which the portable device 110 is located using amultiangulation-based approach (described herein).

The system 100 may, alternately or additionally, determine distanceusing a time-of-flight-/time-of-arrival-(TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.2.b Other AoA-Only Systems

An example embodiment of a twelve (12) antenna system has beendescribed. It is possible to implement systems using more or lessantennas 312 while still using the identified methods. For example:

-   -   Twelve (12) antenna systems with different placements from the        described system.    -   Ten (10) antenna systems, with six (6) external and four (4)        internal antennas 312, that may be limited in their ability to        determine front and rear near zones 400.    -   Eight (8) antenna systems, with four (4) external and four (4)        internal antennas 312, that may be more limited in their ability        to determine outside near zones 400.    -   Eight (8) antenna systems without any internal antennas 312 that        may not provide an inside determination, but provide outside        zones 400.    -   Four (4) antenna systems without any external antennas 312 that        may provide only inside determinations, or that rely upon inside        antennas 312 to determine outside zones 400.    -   Sixteen (16) antenna systems that provide many very precise        zones 400.    -   And so on.

In the illustrated embodiments of FIGS. 31-43 and 67, some of thepossible alternate inside and outside antenna configurations are shown;these configurations, or other configurations not shown, may be combinedto produce angle-based systems of varying characteristics (e.g.,precision/accuracy, number of possible zones 400, redundancy, 2D versus3D coverage, etc.).

In the case of each embodiment, the system 100 may, alternately oradditionally, determine the zone 400 in which the portable device 110 islocated using a multiangulation-based approach (described herein).

In the case of each embodiment, the system 100 may, alternately oradditionally, determine distance using atime-of-flight-/time-of-arrival- (TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.3 Inside/Outside Vehicle Microlocation Embodiment with Angle ofArrival and RSSI

In these systems (subsequently referred to as AoA-RSSI systems), RSSIand/or angle of arrival may be used to position the device relative tothe vehicle 500 (e.g., using a heuristic fingerprint, probabilisticheuristics, trilateration, multilateration, multiangulation,multiangulateration, etc.). RSSI and angle of arrival readings may beobtained using the sniffing approach, as described herein; however, theembodiments themselves need not utilize a particular architecture toobtain readings. It is noted that angle of departure (AoD) may be usedinstead of angle of arrival (AoA), as well as any of the angle ofarrival/departure methods described herein; however, the disclosuresbelow simply refer to all possible implementations where an angle isused (i.e., AoA and AoD may be used interchangeably, and angle may referto either methodology).

In one or more of the embodiments described herein, the system 100 mayprovide, for each reported zone 400, a correctness likelihood indicator(e.g., a confidence score/metric, a likelihood score/metric, probabilityrelative to other reported zones 400 and/or the current zone 400, etc.).

It is noted that these disclosures refer to antennas 312, which, whenmeasuring the angle of a signal, as described herein in this disclosure,may actually be an antenna array. As described herein, any given sensor310 may be connected to multiple antennas 312 (or antenna arrays), andany given antenna 312 (or antenna array) may be connected to multiplesensors 310.

It is noted that, as described elsewhere, said antennas 312 may provideone or more angle measurements (e.g., horizontal, vertical, orhorizontal and vertical angle measurements, etc.). For example, anantenna 312 that reports a vertical angle may provide the system 100with the ability to estimate the vertical position (e.g., distance toground) of a portable device 110 relative to a vehicle 500.

It is noted that, as described herein, angle-measuring sensors may useRSSI to distinguish between relevant and irrelevant signals (e.g.,reflections, signals that are too far away, etc.), whether usingthresholds or other signal analysis techniques (e.g., significantlylower than other signals, etc.).

Sensors 310 may report (i.e., measure and make available to othersensors 310 for use) angle, RSSI, a differential (RSSI or angle), or anycombination thereof. AoA-RSSI systems may be composed of any combinationof sensor types (e.g., sensors 310 that report only angle, sensors 310that report only RSSI, sensors 310 that report both, etc.). For example,a system 100 may be composed of some number of sensors 310 that reportangles and some number of sensors 310 that report RSSI. Alternatively,for example, a system 100 may be composed entirely of sensors 310 thatboth report angle and RSSI. Sensors that report both angle and RSSI maydo so using a single antenna 312 (measuring both angle and RSSI usingone antenna 312 [i.e., antenna array]), using multiple antennas 312(e.g., measuring RSSI using one antenna and measuring angle usinganother, separate antenna array), or any combination thereof. Theappropriate combination of sensors 310 (and antennas 312), along withtheir design and specifications (e.g., measurement/approximation error,sensitivity, size, communications mediums, etc.) for a particularAoA-RSSI system depends upon its application and cost/performancerequirements.

It is noted that distance may be computed from RSSI or angle (viamultiangulation); therefore, wherever distance is used, RSSI or angle(or any other unit/derivation of RSSI or angle) may be substitutedand/or added; likewise, wherever RSSI or angle (or any otherunit/derivation of RSSI or angle) is used, distance may be substitutedand/or added. There exist methods where distance is determined withoutrelying upon RSSI or angle, such as via time-of-flight/time-of-arrival(TOF/TOA) and time-difference-of-arrival (TDOA); the usage of RSSI,angle, and/or distance in this disclosure is not intended to limit orprevent the usage of TOF, TDOA, or alternate methods, and as such,wherever distance, RSSI, and/or angle is used in reference to distancemeasurement/evaluation, distance may refer to distance computed by suchalternate methods, and RSSI or angle may be substituted with the sourcemeasurement (e.g., time, delta time, etc.).

In an AoA-RSSI system, related (correlated) angle and distancemeasurements (e.g., angle and RSSI measurements from the same position)may be referred to as <angle, distance> pairs, which may be provided, asdescribed above, via one sensor 310 using one or more antennas 312(e.g., from a sensor 310 with one antenna array 312 that provides bothangle and distance, from a sensor 310 with an antenna array 312 thatprovides angle and another antenna 312 that provides distance, from asensor 310 with multiple antenna arrays 312 that provides multiple<angle, distance> pairs, etc.), via multiple sensors 310 using one ormore antennas 312 (e.g., one sensor 310 may provide angle and anothernearby sensor 310 may provide distance, etc.), or any combinationthereof. It is noted, that as described herein, <angle> may be an anglerelative to a horizontal axis, a vertical axis, or any other axis, orin-fact, multiple angle measurements (e.g., <angle_(H), angle_(V)> fromboth horizontal and vertical axes). Any given sensor 310 may reportmultiple <angle, distance> pairs (e.g., one sensor 310 may be connectedto multiple antennas 312, with each antenna 312 located with differentfields of view and/or in different positions on the equipment [e.g.,inside and outside], etc.). In an AoA-RSSI system using the sniffingapproach described herein, <angle, distance> pairs may be obtained fromthe same signal transmission across many antennas 312 and thus may beadditionally temporally-, frequency-, and spatially-correlated. The<distance> component may include a distance relative to the portabledevice 110 (absolute or delta), a distance relative to one or more otherantennas 312/sensors 310 (e.g., delta distances, similar to adelta-based multilateration approach), or any combination thereof.Similarly, the <angle> component may include one or more angles relativeto the portable device 110 (absolute or delta), one or more anglesrelative to one or more other antennas 312/sensors 310 (e.g., deltaangles, similar to a delta-based multilateration approach), or anycombination thereof. In the provided example embodiments, antenna312/sensor 310 position (and corresponding position information) isfixed (static); however, alternate embodiments exist where antenna312/sensor 310 position may be partially dynamic (i.e., may move fromone position to some number of other positions based upon equipmentstate [e.g., an antenna 312/sensor 310 on a door 142, etc.]) or fullydynamic (i.e., corresponding position information is determined inreal-time [e.g., by alternate systems/methods, by using other fixedantennas 312/sensors 310, etc.]).

Both RSSI- and angle-based systems, and the techniques used within themto position devices within zones 400, have been described. Individually,each of these systems, when using the methods/techniques described inthis disclosure, perform amazingly well, each with various possibleadvantages (strengths) and possible disadvantages (weaknesses). BecauseRSSI- and AoA-based systems operate on different data (RSSI vs. angle),they have different failure modes (and some of the same failure modes,but that occur in different scenarios). To provide improved performanceand robustness, particularly in systems that operate usingcommunications mediums that are susceptible to reflections andattenuations from common objects (like metal and water), such as BLE,RSSI-based and angle-based techniques may be combined in a way thattakes possible advantage of the differences in the systems' failuremodes.

The disclosed RSSI and AoA systems and/or techniques may be combined, totake possible advantage of their strengths and the differences in theirfailure modes, using the methods and techniques subsequently disclosedherein, resulting in AoA-RSSI systems that may provide improvedperformance and robustness, as compared to RSSI-only and angle-onlysystems, while also mitigating failure modes that neither system 100 mayindividually overcome. For example, systems that operate using BLE aresusceptible to signal reflections and attenuations from common objects(e.g., metal, water, human bodies, wood, etc.), and thus, mayincorrectly determine a device is positioned within, or not within, aparticular zone 400, as a result of said signal reflections and/orattenuations.

AoA-RSSI systems may use RSSI and AoA techniques in any combination atany given time: AoA-RSSI systems may incorporate both RSSI and AoAtechniques for all zone decisions or they may only incorporate both RSSIand AoA techniques in certain situations and/or zone decisions, usingonly RSSI or AoA techniques in other situations and/or zone decisions(e.g., a system 100 may use RSSI and AoA to determine a certain set ofoutside zones 400 and use only RSSI to determine whether a device is inan inside zone 400).

As described above, RSSI-only and angle-only systems may each havedifferent failure modes. Signal reflections and blockers may affect RSSIand angle differently (for each transmitter/receiver orientation, aswell as for each channel/frequency, in RF-based systems, such as BLE).

For example, RSSI may be stronger or weaker due to reflections orblockers that enable or disable propagation paths to antennas 312 from aparticular location that normally may be disabled or enabled,respectively (e.g., if a portable device 110 is two meters from the rearof a vehicle 500, the maximum RSSI of the inside antennas 312 may besignificantly higher when the vehicle 500 is located within a commercialgarage with a metal roof, than it is when it is located within aresidential garage, than it is when it is located in an open field; if aperson is located between a portable device 110 and an antenna 312, theRSSI measurements of signals from said portable device 110 to saidantenna 312 may be significantly lower than without a person locatedbetween them; if a vehicle 500 is parked amongst other vehicles 500, thenearby vehicles 500 may produce reflections that cause the maximum RSSIof the inside antennas 312 to be higher than normal at a particulardistance; etc.).

The RSSI differential technique, when used with the sniffingarchitecture as described herein, is substantially immune toreflections/blockers; however, RSSI-based distance calculations andRSSIs (i.e., not differentials) may be vulnerable toreflections/blockers (which is where angles may provide someassistance).

As another example, angle measurements may be erratic due toreflections, as the angles of reflections may be measured, instead ofthe angles of direct signals from the portable device 110 (e.g., due toconstructive/destructive interference [fast fading], if a vehicle 500 isparked on the driver side of a vehicle 500, and the portable device 110is located on the driver side of said vehicle 500, antennas 312 maymeasure the angle of the signal reflected off the nearby parked vehicle500, as opposed to not receiving said signal, etc.).

Angle measurements are not made stronger or weaker due to reflections(they are instead made more reliable by being within the field of view412 of an antenna 312); as disclosed herein, angle of arrival techniquesto filter invalid measurements are employed, and when using the sniffingarchitecture, may be filtered over and correlated with all availablechannels/frequencies and other antennas 312/sensors 310. Coupled withRSSI information obtained and filtered using the sniffing architecturemay also provide additional insight into the validity of various signalmeasurements.

By combining angle of arrival with the RSSI techniques disclosed tobound zones 400, an AoA-RSSI system may provide higher near zonedetermination accuracy, as well as resilience against situations wherethe device is actually outside the zone 400, but appears to be withinthe zone 400, or appears to be outside the zone 400, but is actuallyinside the zone 400, due to reflections. These failure mode differences,as well as others, may be exploited for all zones 400—inside, outside,near, far, distance-based, or differential-based.

The following sections describe embodiments of a number of possibleAoA-RSSI systems and their methods. It is noted that AoA-RSSI systemsmay use the previously described RSSI- and angle-based methods, thecombined methods described below, time-of-flight (TOF),time-difference-of-arrival (TDOA), trilateration, multilateration,multiangulation, multiangulateration, or any combination thereof. It isalso noted that said systems may integrate the results of positioningmethods (within one method or to integrate the results of multiplemethods) using any combination of disclosed methods, including, but notlimited to, the subsequently disclosed combination methods, Kalmanfilters, particle filters, probabilistic estimation/filters,fingerprinting, and heuristics.

E.3.a Twenty-Three (23) Antenna AoA RSSI System (12 AoA+11 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 49, the system 100 may use angle of arrival (AoA) andRSSI. The system 100 may include twenty-three (23) antennas 312. In thissystem 100, the twelve (12) antenna AoA system (as described in SectionE.2.a, antennas 312-1 through 312-12) and eleven (11) antenna RSSIsystem (as described in Section E.1.c, antennas 312-13 through 312-23)are combined, using the antennas 312 (RSSI-only and angle-only) andantenna placements previously described for each respective system 100.It is noted that this may be considered a naïve embodiment of a combinedAoA-RSSI system, and as such, more efficiency may be gained withalternate embodiments that use sensors 310 that report both angle andRSSI together, with more efficient/combined placement (such embodimentsare described herein in this disclosure); however, the methods andtechniques used with this embodiment may be used in subsequentlydescribed embodiments.

In this system 100, the portable device 110 communicates with a masterdevice 120 located on the interior of the vehicle 500 that is separatefrom the twenty-three (23) antennas 312 identified above.

This system 100 may be capable of determining at least the followingzones 400: A) inside, B) outside near driver side, C) outside nearpassenger side, D) outside near tailgate/trunk, E) outside near front,F) not near the vehicle 500, but within one or more secondarythresholds, G) not near the vehicle 500, but connected, and H) notconnected.

In addition to A, the system 100 may also determine one or more of thefollowing zones 400: A_(DF) (interior driver front), A_(PF) (interiorpassenger front), A_(DR) (interior driver rear), A_(DF) (interiorpassenger rear), A_(T) (interior trunk).

The above zones 400, along with the field of view 412 of each AoAantenna 312, and example thresholds that may be used to define zones 400for both AoA and RSSI antennas 312 (with measurement/approximation errormarkers), are depicted in the illustrated embodiment of FIG. 49.

Additional (or fewer) zones 400 may be defined, with varying levels ofaccuracy. For example, another outside zone 400 may be defined outsideof the near zones 400, that extends further away from the vehicle 500,zone F may not exist, or additional near zones 400 at various angles maybe defined. Vertical zones 400 may also be defined, also with varyinglevels of accuracy. For example, low, medium, and high vertical zones400 may be defined for near zones 400. The ability of the system 100 toaccurately determine whether or not the device is located within whatzone 400 may be limited by the underlying capabilities of thecommunications medium (e.g., BLE vs. UWB vs. LF) and accuracy of RSSIand angle measurement facilities (e.g., measurement/approximationerror).

The system 100 may use any combination of RSSI-based and/or angle-basedmethods to determine presence within (or absence from) a particular zone400 (e.g., using only RSSI, using only angles, requiring agreementbetween both RSSI- and angle-based methods, requiring agreement betweenboth RSSI- and angle-based methods only when certain thresholds are [orare not] satisfied and/or when both are able to determine a zone 400,requiring one of RSSI- and angle-based methods, selecting the methodthat yields the most probable position [e.g., based on probability, withthe greatest margin, etc.], etc.).

The system 100 may use RSSI-based methods to determine or alter whichangle-based methods, antenna 312 combinations, threshold combinations,thresholds, or any combination thereof, are used to determine that aportable device 110 is located in a particular zone 400 or at aparticular distance (e.g., if an RSSI-based method determines aparticular zone 400 [e.g., zone B], the criteria utilized of anangle-based method may be relaxed [e.g., adjust zone B thresholds to beslightly more inclusive than normal]); likewise, the system 100 may useangle-based methods to determine or alter which RSSI-based methods,antenna 312 combinations, threshold combinations, thresholds, or anycombination thereof, are used to determine that a portable device 110 islocated in a particular zone 400 or at a particular distance (e.g., ifan angle-based method determines a particular zone 400 [e.g., zone B],the criteria utilized of an RSSI-based method may be relaxed [e.g.,adjust zone B thresholds to be slightly more inclusive than normal], ifan angle-based method determines that the portable device 110 is near aparticular zone 400 at a particular approximate height, the criteriautilized of an RSSI-based method may be tightened [e.g., adjust zone Bthresholds to be slightly more restrictive than normal], etc.).

As described previously, variance (or noise) in measured RSSI and/orangles, from a portable device 110 and/or other system antennas 312(including a master device 120 antenna 312), and measured backgroundpower/noise, may allow the system 100 to determine the presence (orabsence) of nearby objects (e.g., vehicles 500, people, etc.) and/orwhether the system 100 is located within certain environments (e.g., ahighly reflective environment). The previously described RSSI- andangle-based methods may be used separately or together to make suchdeterminations and/or adjustments.

In one embodiment, the system 100, when it has determined that a vehicle500 or object is nearby, such as by observing variance on only a fewchannels using both RSSI- and angle-based methods, as described above,the distance to said vehicle 500 or object may computed usingmultiangulation (e.g., triangulation), multiangulateration, any otherdisclosed method, or any combination thereof.

The system 100 may use different combination methods to combinepositioning method results at different times (e.g., the system 100 mayutilize agreement between both RSSI- and angle-based methods totransition into or out of a zone 400, but may utilize only one of RSSI-and angle-based methods to remain in said zone 400, etc.). Depending onboth methods agreeing (in the presence in—or absence from—a particularzone 400) may reduce the probability that the system 100 determines anincorrect zone 400, at the expense of focusing on the portable device110 being more clearly within a particular zone 400 (i.e., within all ofthe applicable thresholds from both systems); this may result in certainsituations in which a particular zone determination is desired, butwhere the system 100 is unable to provide such determination (e.g.,cases at the edge of certain thresholds, in certain positions thatpresent challenges due to reflectors or blockers, etc.). Conversely,requiring only one of the methods increases the probability that thesystem 100 may determine a particular zone 400, at the expense ofpotentially determining an incorrect zone 400; this may result incertain situations in which a particular zone determination is notdesired, but where the system 100 is unable to prevent suchdetermination (e.g., cases at the edge of certain thresholds, in certainpositions that present challenges due to reflectors or blockers, etc.).

The appropriate selection of when to utilize agreement, or when not to,depends on the desired behavior of the system 100, and may be determineda priori, statically, or dynamically for each zone 400 in each system100. For most systems, the optimal or selected combination of methodsfor a particular zone 400 may vary dynamically based upon the previouszone 400 and candidate zones 400 (i.e., the sort of zone transition),the set of candidate zones 400 themselves (i.e., are the RSSI- andangle-based methods determining zones 400 nearby to one another or farapart), concreteness of the candidate zones 400 (i.e., is one candidatezone 400 barely probable, but another highly probable), the set ofthresholds that are (or aren't) satisfied, whether a particular methodis able to determine a zone 400 (i.e., if the angle-based method is notable to determine a zone 400, but the RSSI-based method is, or viceversa), other related criteria (e.g., other vehicle sensors, portabledevice 110 sensors, sensor 310 state/diagnostics, etc.), or anycombination thereof.

In one embodiment, positioning results may be alternately oradditionally combined using a particle filter. In another embodiment,positioning results may be alternately or additionally combined using aKalman filter. In yet another embodiment, positioning results may bealternately or additionally combined using probabilistic models offeasible state/zone transitions. In yet another embodiment, positioningresults may be alternately or additionally combined usingfingerprinting.

In any embodiment, it is noted that additional sensor information, suchas those described previously (e.g., portable device 110 or system 100provided INS [e.g., accelerometer, magnetometer, gyroscope, etc.],ultrasonic, step counting, etc.), may be integrated into antenna 312measurements, signal processing techniques, zone determination methods,position combination methods, any other disclosed method or technique,or any combination thereof.

With regard to angle-based antennas 312, the field-of-view of one ormore antennas 312 may be restricted, or the measurement/approximationerror of one or more antennas 312 may be significant, such thatthresholds associated with said antennas 312 may be restricted,resulting in zone boundaries that are either smaller, larger, or lessaccurate than desired. In such situations, to reach agreement, it may beadvantageous to relax or tighten one or more thresholds of theangle-based methods, when the RSSI-based methods determine that theportable device 110 is (or is not) located in one of these zones 400.For example, if RSSI-based methods determine that the portable device110 is located in zone B, one or more thresholds for angle-based methodsmay be relaxed to form a larger angle-based zone B (thus increasing theprobability that the angle-based method determines that the portabledevice 110 is located in zone B [e.g., because the angle-based system byitself results in closer than desired boundaries]).

With regard to RSSI-based antennas 312, the field-of-view (i.e.,radiation pattern) of one or more antennas 312 may be restricted, or themeasurement/approximation error of one or more antennas 312 may besignificant, such that thresholds associated with said antennas 312 maybe restricted, resulting in zone boundaries that are either smaller,larger, or less accurate than desired. In such situations, to reachagreement, it may be advantageous to relax or tighten one or morethresholds of the RSSI-based methods, when the angle-based methodsdetermine that the portable device 110 is (or is not) located in one ofthese zones 400. For example, if angle-based methods determine that theportable device 110 is located in zone B, one or more thresholds forRSSI-based methods may be relaxed to allow a larger RSSI-based zone B(thus increasing the probability that the RSSI-based method determinesthat the portable device 110 is located in zone B [e.g., because theRSSI-based system 100 by itself results in closer than desiredboundaries]). For example, if an angle-based method determines that theportable device 110 is near a particular zone 400 at a particularapproximate height, the criteria utilized of an RSSI-based method may betightened (e.g., adjust zone B thresholds to be slightly morerestrictive than normal, or use alternate thresholds, formulas, ormethods to compute distance [e.g., because the portable device 110 maybe located in a position in which the RSSI-based methods measure signalsmore strongly]).

It is noted that, as previously disclosed, zones 400 may be determinedby taking possible advantage of one set of methods indicating presenceand another indicating absence, and/or that one or more methods may besupported by a presence of measurements and one or methods may besupported by an absence of measurements. Reaching agreement amongstRSSI-based and angle-based methods may also take possible advantage ofthese properties, as such, agreement may include the presence or absencein a particular zone 400 and/or the presence or absence of measurementsfrom the portable device 110 (or any other data source [e.g., vehiclesensors, portable device 110 sensors, etc.]). For example, RSSI-basedmethods may determine that the portable device 110 is located in zone B,but angle-based methods may not provide a determination; in the casewhere no measurements were obtained from angle-based antennas 312, thesystem 100 may not consider both methods as in agreement; however, inthe case where measurements were only not obtained from certain antennas312, the system 100 may consider the angle-based methods as inagreement. For example, the system 100 may determine that, due to anRSSI-based method determination of zone B, and an angle-based methoddetermination that the portable device 110 is absent from zone B, C, andE, that the portable device 110 is positioned in zone B.

The system 100 may distinguish zone A (inside) from other zones 400using the methods previously described for RSSI-based and angle-basedsystems. The system 100 may utilize that both RSSI- and angle-basedmethods agree that the portable device 110 is located in zone A todetermine that the portable device 110 is located in zone A.Alternatively, the system 100 may only utilize that either RSSI- orangle-based methods determine that the portable device 110 is located inzone A to determine that the portable device 110 is located in zone A;such an approach may additionally utilize that one or more thresholds besatisfied (which may include requiring that a particular approach have aminimum amount of margin in its decision process). Alternatively, thesystem 100 may utilize that both RSSI- and angle-based methods agreethat the portable device 110 is located in zone A to transition thedetermined position of the portable device 110 from any other zone tozone A, but only utilize that either RSSI- or angle-based methodsdetermine that the portable device 110 is located in zone A to remainlocated in zone A when one or more thresholds have not been reached(e.g., remain in zone A if is not apparent that the portable device 110is positioned in another zone 400, remain in zone A if the system 100cannot determine that the portable device 110 is positioned in any otherzone 400, etc.).

The system 100, when it has determined that the portable device 110 isin zone A (inside), may determine whether the portable device 110 islocated in zone A_(DF), A_(PF), A_(DR), A_(PR), or A_(T) using themethods previously described for RSSI-based and angle-based systems.Similar to zone A, the system 100 may utilize agreement amongst RSSI-and angle-based methods to determine in which of these zones 400 aportable device 110 is located. Alternatively, the system 100 may selectthe most probable zone 400 by using the determined zone 400 with themost margin and greatest probability (e.g., if RSSI-based methodsdetermine A_(DF), and approach-based methods determine A_(PF), and theRSSI-based methods concretely determined A_(DF) [i.e., it is veryunlikely to be any other zone 400—there is a lot of margin in theselected zone 400], and the approach-based method loosely determinedA_(PF) [i.e., the decision was right on the edge, and it may not takemuch to determine another zone 400—there is not a lot of margin in theselected zone 400], then the system 100 may determine A_(DF) [and mayinstead not determine a zone 400 if both are concrete or loose, or ifinstead both methods result in zones 400 that are not nearby], etc.).

The system 100 may distinguish zones B-E from F by applying an approachsimilar to that as used to determine zones A, A_(DF), A_(PF), A_(DR),A_(PR), and/or A_(T). The system 100 may utilize agreement amongst RSSI-and angle-based methods to determine in which of these zones 400 aportable device 110 is located. Alternatively, the system 100 may selectthe most probable zone 400 by using the determined zone 400 with themost margin and greatest probability (e.g., if RSSI-based methodsdetermine B, and approach-based methods determine D, and the RSSI-basedmethods concretely determined B [i.e., it is very unlikely to be anyother zone 400—there is a lot of margin in the selected zone 400], andthe approach-based method loosely determined D [i.e., the decision wasright on the edge, and it may not take much to determine another zone400—there is not a lot of margin in the selected zone 400], then thesystem 100 may determine B [and may instead not determine a zone 400 ifboth are concrete or loose, or if instead both methods result in zones400 that are not nearby], etc.).

The system 100 may distinguish zone F by applying an approach similar tothat as used to determine zones B-E. The system 100 may utilizeagreement amongst RSSI- and angle-based methods to determine that theportable device 110 is located zone F. For example, angle-based methodsmay not define zone F, in which case, the system 100 may utilize thatRSSI-based methods determine that the portable device 110 is located inzone F and that angle-based methods determine that the portable device110 is not present in zones A-E; alternatively, angle-based methods maydefine zone F, in which case, the angle-based system 100 may also beutilized to determine that the portable device 110 is located in zone F.Alternatively, the system 100 may select the most probable zone 400 byusing the determined zone 400 with the most margin and greatestprobability (e.g., if RSSI-based methods determine F, and approach-basedmethods determine B, and the RSSI-based methods concretely determined F[i.e., it is very unlikely to be any other zone 400—there is a lot ofmargin in the selected zone 400], and the approach-based method looselydetermined B [i.e., the decision was right on the edge, and it may nottake much to determine another zone 400—there is not a lot of margin inthe selected zone 400], then the system 100 may determine F [or mayinstead determine zone B, if both are concrete, or one method determineszone G], etc.).

The system 100 may distinguish zone G by applying an approach similar tothat as used to determine zone F. The system 100 may utilize agreementamongst RSSI- and angle-based methods to determine that the portabledevice 110 is located zone G. For example, angle-based methods may notdefine zone G, in which case, the system 100 may utilize that RSSI-basedmethods determine that the portable device 110 is located in zone G andthat angle-based methods determine that the portable device 110 is notpresent in zones A-F; alternatively, angle-based methods may define zoneG, in which case, the angle-based system 100 may also be utilized todetermine that the portable device 110 is located in zone G.Alternatively, the system 100 may select the most probable zone 400 byusing the determined zone 400 with the most margin and greatestprobability (e.g., if RSSI-based methods determine G, and approach-basedmethods determine B or F, and the RSSI-based methods concretelydetermined G [i.e., it is very unlikely to be any other zone 400—thereis a lot of margin in the selected zone 400], and the approach-basedmethod loosely determined B or F [i.e., the decision was right on theedge, and it may not take much to determine another zone 400—there isnot a lot of margin in the selected zone 400], then the system 100 maydetermine G [or may instead determine zone F, if both are concrete, orB, depending upon the level of concreteness or other conditions], etc.).

The system 100 may determine the position of the portable device 110 tobe in zone H, if the portable device 110 is not connected.

The system 100 may, alternately or additionally, determine the zone 400in which the portable device 110 is located using a trilateration-,multilateration-, multiangulation-, or multiangulateration-basedapproach, or any combination thereof (described herein).

The system 100 may, alternately or additionally, determine distanceusing a time-of-flight-/time-of-arrival-(TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.3.b Twenty-One (21) Antenna AoA RSSI System (10 AoA+11 RSSI)

The above twenty-three (23) antenna AoA-RSSI system embodiment, withoutthe front-facing front AoA antennas 312 (antennas 312-2, 312-3).

E.3.c Twenty-One (21) Antenna AoA RSSI System (10 AoA+11 RSSI, No Rear)

The above twenty-three (23) antenna AoA-RSSI system embodiment, withoutthe rear-facing rear AoA antennas 312 (antennas 312-6, 312-7).

E.3.d Nineteen (19) Antenna AoA RSSI System (8 AoA+11 RSSI, NoFront/Rear)

The above twenty-three (23) antenna AoA-RSSI system embodiment, withoutthe front-facing front and rear-facing rear AoA antennas 312 (antennas312-2, 312-3, 312-6, 312-7).

E.3.e Nineteen (19) Antenna AoA-RSSI System (8 AoA+11 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 50, the system 100 may use angle of arrival (AoA) andRSSI with nineteen (19) antennas 312. In this system 100, an eight (8)antenna AoA system (antennas 312-1 through 312-8), which is a variationof the twelve (12) antenna AoA system (as described in Section E.2.a)without inside antennas, and an eleven (11) antenna RSSI system (asdescribed in Section E.1.c, antennas 312-9 through 312-19), arecombined, using the antennas (RSSI-only and angle-only) and antennaplacements previously described for each respective system 100. It isnoted that this may be considered a naïve embodiment of a combinedAoA-RSSI system, and as such, more efficiency may be gained withalternate embodiments that use sensors 310 that report both angle andRSSI together, with more efficient/combined placement (such embodimentsare described herein in this disclosure); however, the methods andtechniques used with this embodiment may be used in subsequentlydescribed embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system 100 previously described.

For the purposes of disclosing this nineteen (19) antenna AoA-RSSIsystem 100, it is assumed that the set of potential zones 400 is thesame set as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system; however, as also previously disclosed, thesystem 100 may use additional and/or fewer zones 400, with the same ordifferent boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed RSSI-based methods. Additionally, or alternatively,as previously disclosed, AoA antennas 312 may participate in interiorzone determination (e.g., if the field-of-view of the exterior AoAantennas 312 allow it, etc.).

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are depicted in theillustrated embodiment of FIG. 50.

E.3.f Seventeen (17) Antenna AoA-RSSI System (6 AoA+11 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 51, the system 100 may uses angle of arrival (AoA) andRSSI with seventeen (17) antennas 312. In this system 100, a six (6)antenna AoA system (antennas 312-1, 312-4 through 312-8), which is avariation of the twelve (12) antenna AoA system (as described in SectionE.2.a) without inside and front-facing front antennas 312, and an eleven(11) antenna RSSI system (as described in Section E.1.c, antennas 312-9through 312-19), are combined, using the antennas 312 (RSSI-only andangle-only) and antenna placements previously described for eachrespective system 100. It is noted that this may be considered a naïveembodiment of a combined AoA-RSSI system, and as such, more efficiencymay be gained with alternate embodiments that use sensors 310 thatreport both angle and RSSI together, with more efficient/combinedplacement (such embodiments are described herein in this disclosure);however, the methods and techniques used with this embodiment may beused in subsequently described embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this seventeen (17) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system, without the front near zone 400; however, asalso previously disclosed, the system 100 may use additional and/orfewer zones 400, with the same or different boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed RSSI-based methods. Additionally, or alternatively,as previously disclosed, AoA antennas 312 may participate in interiorzone determination (e.g., if the field-of-view of the exterior AoAantennas 312 allow it, etc.).

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 51.

E.3.g Fifteen (15) Antenna AoA RSSI System (4 AoA+11 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 52, the system 100 may use angle of arrival (AoA) andRSSI with fifteen (15) antennas 312. In this system 100, a four (4)antenna AoA system (e.g., antennas 312-1, 312-4, 312-5, 312-8), which isa variation of the twelve (12) antenna AoA system (as described inSection E.2.a) without inside, front-facing front, and rear-facing rearantennas 312, and an eleven (11) antenna RSSI system (as described inSection E.1.c, antennas 312-7 through 312-17), are combined, using theantennas 312 (RSSI-only and angle-only) and antenna placementspreviously described for each respective system 100. It is noted thatthis may be considered a naïve embodiment of a combined AoA-RSSI system,and as such, more efficiency may be gained with alternate embodimentsthat use sensors 310 that report both angle and RSSI together, with moreefficient/combined placement (such embodiments are described herein inthis disclosure); however, the methods and techniques used with thisembodiment may be used in subsequently described embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system 100 previously described.

For the purposes of disclosing this fifteen (15) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system, without the front near zone 400; however, asalso previously disclosed, the system 100 may use additional and/orfewer zones 400, with the same or different boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed RSSI-based methods. In this system 100, the one ormore exterior rear zones 400 (e.g., D) may be determined using thepreviously disclosed RSSI-based methods. Additionally, or alternatively,as previously disclosed, AoA antennas 312 may participate in interior orexterior rear zone determinations (e.g., if the field-of-view of theexterior AoA antennas 312 allow it, etc.).

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are depicted in theillustrated embodiment of FIG. 52.

In the illustrated embodiment of FIG. 53, an alternate embodiment ofthis fifteen (15) antenna AoA-RSSI system is shown, wherein thepositions and fields of view for AoA antennas 312 (312-1, 312-4, 312-5,312-8) are moved slightly (e.g., to illustrate less optimal side zonecoverage, with the potential for some rear zone coverage).

E.3.h Fifteen (15) Antenna AoA RSSI System (8 AoA+7 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 54, the system 100 may use angle of arrival (AoA) andRSSI with fifteen (15) antennas 312. In this system 100, an eight (8)antenna AoA system (antennas 312-1 through 312-8), which is a variationof the twelve (12) antenna AoA system (as described in Section E.2.a)without inside antennas 312, and a seven (7) antenna RSSI system(antennas 312-9 through 312-12, 312-15, 312-16, 312-19), which is avariation of the eleven (11) antenna RSSI system (as described in E.1.c)without rear driver side and rear passenger side antenna pairs (i.e.,equivalent to the seven [7] antenna RSSI system described in E.1.b), arecombined, using the antennas 312 (RSSI-only and angle-only) and antennaplacements previously described for each respective system 100, exceptfor possibly antennas 312-9 through 312-12. In this system 100, antennas312-9 through 312-12 may use the previously described placements, oralternately, they may be moved more towards the center of the sides ofthe vehicle 500, such as on or near the B-pillar or door handle.

It is noted that this may be considered a naïve embodiment of a combinedAoA-RSSI system, and as such, more efficiency may be gained withalternate embodiments that use sensors 310 that report both angle andRSSI together, with more efficient/combined placement (such embodimentsare described herein in this disclosure); however, the methods andtechniques used with this embodiment may be used in subsequentlydescribed embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this fifteen (15) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system; however, as also previously disclosed, thesystem 100 may use additional and/or fewer zones 400, with the same ordifferent boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed RSSI-based methods. For example, in one embodiment,only interior zone A may be determined; in another embodiment, onlyzones A and A_(T) may be determined; in yet another embodiment, onlyzones A, AD (driver side interior, combining A_(DF) and A_(DR)), A_(P)(passenger side interior, combining A_(PF) and A_(PR)), and A_(T) may bedetermined. Additionally, or alternatively, as previously disclosed, AoAantennas 312 may participate in interior zone determination (e.g., ifthe field-of-view of the exterior AoA antennas 312 allow it, etc.).

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 54.

E.3.i Thirteen (13) Antenna AoA-RSSI System (6 AoA+7 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 55, the system 100 may use angle of arrival (AoA) andRSSI with thirteen (13) antennas 312. In this system 100, a six (6)antenna AoA system (antennas 312-1, 312-4 through 312-8), which is avariation of the twelve (12) antenna AoA system (as described in SectionE.2.a) without inside and front-facing front antennas 312, and a seven(7) antenna RSSI system (antennas 312-9 through 312-12, 312-15, 312-16,312-19), which is a variation of the eleven (11) antenna RSSI system (asdescribed in E.1.c) without rear driver side and rear passenger sideantenna pairs (i.e., equivalent to the seven [7] antenna RSSI systemdescribed in E.1.b), are combined, using the antennas (RSSI-only andangle-only) and antenna placements previously described for eachrespective system 100, except for possibly antennas 312-9 through312-12. In this system 100, antennas 312-9 through 312-12 may use thepreviously described placements, or alternately, they may be moved moretowards the center of the sides of the vehicle 500, such as on or nearthe B-pillar.

It is noted that this may be considered a naïve embodiment of a combinedAoA-RSSI system, and as such, more efficiency may be gained withalternate embodiments that use sensors 310 that report both angle andRSSI together, with more efficient/combined placement (such embodimentsare described herein in this disclosure); however, the methods andtechniques used with this embodiment may be used in subsequentlydescribed embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this thirteen (13) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system, without the front near zone 400; however, asalso previously disclosed, the system 100 may use additional and/orfewer zones 400, with the same or different boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed RSSI-based methods. For example, in one embodiment,only interior zone A may be determined; in another embodiment, onlyzones A and A_(T) may be determined; in yet another embodiment, onlyzones A, AD (driver side interior, combining A_(DF) and A_(DR)), A_(P)(passenger side interior, combining A_(PF) and A_(PR)), and A_(T) may bedetermined. Additionally, or alternatively, as previously disclosed, AoAantennas 312 may participate in interior zone determination (e.g., ifthe field-of-view of the exterior AoA antennas 312 allow it, etc.).

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are depicted in theillustrated embodiment of FIG. 55.

E.3.j Eleven (11) Antenna AoA RSSI System (4 AoA+7 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 56, the system 100 may use angle of arrival (AoA) andRSSI with eleven (11) antennas 312. In this system 100, a four (4)antenna AoA system (antennas 312-1, 312-4, 312-5, 312-8), which is avariation of the twelve (12) antenna AoA system (as described in SectionE.2.a) without inside, front-facing front, and rear-facing rear antennas312, and a seven (7) antenna RSSI system (antennas 312-9 through 312-12,312-15, 312-16, 312-19), which is a variation of the eleven (11) antennaRSSI system (as described in E.1.c) without rear driver side and rearpassenger side antenna pairs (i.e., equivalent to the seven [7] antennaRSSI system described in E.1.b), are combined, using the antennas 312(RSSI-only and angle-only) and antenna placements previously describedfor each respective system 100, except for possibly antennas 312-9through 312-12. In this system 100, antennas 312-9 through 312-12 mayuse the previously described placements, or alternately, they may bemoved more towards the center of the sides of the vehicle 500, such ason or near the B-pillar or door handle.

It is noted that this may be considered a naïve embodiment of a combinedAoA-RSSI system, and as such, more efficiency may be gained withalternate embodiments that use sensors 310 that report both angle andRSSI together, with more efficient/combined placement (such embodimentsare described herein in this disclosure); however, the methods andtechniques used with this embodiment may be used in subsequentlydescribed embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this eleven (11) antenna AoA-RSSI system,it is assumed that the set of potential zones 400 is the same set asdescribed within the previously disclosed twenty-three (23) antennaAoA-RSSI system, without the front near zone 400; however, as alsopreviously disclosed, the system 100 may use additional and/or fewerzones 400, with the same or different boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed RSSI-based methods. For example, in one embodiment,only interior zone A may be determined; in another embodiment, onlyzones A and A_(T) may be determined; in yet another embodiment, onlyzones A, AD (driver side interior, combining A_(DF) and A_(DR)), A_(P)(passenger side interior, combining A_(PF) and A_(PR)), and A_(T) may bedetermined. In this system 100, the one or more exterior rear zones 400(e.g., D) may be determined using the previously disclosed RSSI-basedmethods. Additionally, or alternatively, as previously disclosed, AoAantennas 312 may participate in interior zone determination (e.g., ifthe field-of-view of the exterior AoA antennas 312 allow it, etc.).

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are depicted in theillustrated embodiment of FIG. 56.

E.3.k Eighteen (18) Antenna AoA RSSI System (12 AoA+6 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 57, the system 100 may use angle of arrival (AoA) andRSSI with eighteen (18) antennas 312. In this system 100, the twelve(12) antenna AoA system (as described in Section E.2.a, antennas 312-1through 312-12), and a six (6) antenna RSSI system (antennas 312-13,312-16, 312-18, 312-20, 312-21, 312-23), which is a variation of theeleven (11) antenna RSSI system (as described in E.1.c) without interiorantennas 312 (except for the center antenna 312), are combined, usingthe antennas 312 (RSSI-only and angle-only) and antenna placementspreviously described for each respective system 100. It is noted thatthis may be considered a naïve embodiment of a combined AoA-RSSI system,and as such, more efficiency may be gained with alternate embodimentsthat use sensors 310 that report both angle and RSSI together, with moreefficient/combined placement (such embodiments are described herein inthis disclosure); however, the methods and techniques used with thisembodiment may be used in subsequently described embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this eighteen (18) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system; however, as also previously disclosed, thesystem 100 may use additional and/or fewer zones 400, with the same ordifferent boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed AoA-based methods. Additionally, or alternatively,as previously disclosed, RSSI antennas 312 may participate in interiorzone determination.

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 57.

E.3.l Fourteen (14) Antenna AoA RSSI System (8 AoA+6 RSSI)

The above eighteen (18) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear AoA antennas (antennas 312-2,312-3, 312-6, 312-7).

E.3.m Seventeen (17) Antenna AoA RSSI System (12 AoA+5 RSSI)

The above eighteen (18) antenna AoA-RSSI system embodiment, without thecenter RSSI antenna (antenna 312-23).

E.3.n Thirteen (13) Antenna AoA RSSI System (8 AoA+5 RSSI)

The above seventeen (17) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear AoA antennas (antennas 312-2,312-3, 312-6, 312-7).

E.3.o Sixteen (16) Antenna AoA-RSSI System (12 AoA+4 RSSI)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 58, the system 100 may use angle of arrival (AoA) andRSSI with seventeen (17) antennas. In this system, the twelve (12)antenna AoA system (as described in Section E.2.a, antennas 312-1through 312-12), and a four (4) antenna RSSI system (antennas 312-13,312-16, 312-20, 312-23), which is a variation of the eleven (11) antennaRSSI system (as described in E.1.c) without rear driver side and rearpassenger side antenna pairs (i.e., equivalent to the seven [7] antennaRSSI system described in E.1.b) and additionally without interiorantennas 312 (except for the center antenna 312), are combined, usingthe antennas 312 (RSSI-only and angle-only) and antenna placementspreviously described for each respective system 100, except for possiblyantennas 312-13 and 312-16. In this system 100, antennas 312-13 and312-16 may use the previously described placements, or alternately, theymay be moved more towards the center of the sides of the vehicle 500,such as on or near the B-pillar or door handle.

It is noted that that this may be considered a naïve embodiment of acombined AoA-RSSI system, and as such, more efficiency may be gainedwith alternate embodiments that use sensors 310 that report both angleand RSSI together, with more efficient/combined placement (suchembodiments are described herein in this disclosure); however, themethods and techniques used with this embodiment may be used insubsequently described embodiments.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this sixteen (16) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system; however, as also previously disclosed, thesystem 100 may use additional and/or fewer zones 400, with the same ordifferent boundaries/definitions.

In this system 100, the one or more interior zones 400 (e.g., A, A_(DF),A_(PF), A_(DR), A_(PR), A_(T), etc.) may be determined using thepreviously disclosed AoA-based methods. Additionally, or alternatively,as previously disclosed, RSSI antennas 312 may participate in interiorzone determination.

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 58.

E.3.p Fifteen (15) Antenna AoA-RSSI System (12 AoA+3 RSSI)

The above sixteen (16) antenna AoA-RSSI system embodiment, without thecenter RSSI antenna 312 (antenna 312-23).

E.3.q Fifteen (15) Antenna AoA RSSI System (12 AoA+3 RSSI, No Rear)

The above sixteen (16) antenna AoA-RSSI system embodiment, without therear exterior RSSI antenna 312 (antenna 312-20).

E.3.r Fourteen (14) Antenna AoA RSSI System (12 AoA+2 RSSI)

The above sixteen (16) antenna AoA-RSSI system embodiment, without thecenter or rear exterior RSSI antennas 312 (antennas 312-20 and 312-23).

E.3.s Twelve (12) Antenna AoA RSSI System (8 AoA+4 RSSI)

The above sixteen (16) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear AoA antennas 312 (antennas 2, 3,6, 7). An example is shown in the illustrated embodiment of FIG. 59.

E.3.t Eleven (11) Antenna AoA RSSI System (8 AoA+3 RSSI)

The above sixteen (16) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear AoA antennas 312 (antennas312-2, 312-3, 312-6, 312-7) and without the center RSSI antenna 312(antenna 312-23).

E.3.u Eleven (11) Antenna AoA RSSI System (8 AoA+3 RSSI, No Rear)

The above sixteen (16) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear AoA antennas 312 (antennas312-2, 312-3, 312-6, 312-7) and without the rear exterior RSSI antenna312 (antenna 312-20).

E.3.v Ten (10) Antenna AoA RSSI System (8 AoA+2 RSSI)

The above sixteen (16) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear AoA antennas 312 (antennas312-2, 312-3, 312-6, 312-7) and without the center or rear exterior RSSIantennas 312 (antennas 312-20 and 312-23).

E.3.w Thirteen (13) Antenna AoA RSSI System (13 Combined)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 60, the system 100 may use angle of arrival (AoA) andRSSI with thirteen (13) combined antennas 312. In this system 100, theantenna 312 placements for the twelve (12) antenna AoA system (asdescribed in Section E.2.a, antennas 312-1 through 312-12) are used,plus an additional center antenna 312 (antenna 312-23) similar to thatin previously described RSSI systems (e.g., as described in SectionE.1.c), but each antenna 312 is a combined antenna 312 (e.g., sensor310) capable of reporting both angle and RSSI (either together orseparately). As previously described, said combined antennas 312(sensors 310) may comprise one or more antennas 312 (or antenna arrays),and may or may not be physically combined/collocated. As previouslydescribed, said combined antennas 312 may provide one or more anglemeasurements (e.g., horizontal, vertical, or horizontal and verticalangle measurements, etc.).

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this thirteen (13) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system; however, as also previously disclosed, thesystem 100 may use additional and/or fewer zones 400, with the same ordifferent boundaries/definitions.

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 60. One concern with this embodiment, as is evidentin the illustration, may be that antenna placement may not provide forspatially-correlated RSSI differentials (i.e., there are antenna pairsthat are not near one another, but that have radiation patterns that areopposite one another). In one embodiment with the illustrated sensorplacement, some or all of the interior sensors 310 may have one antenna312 placed inside measuring RSSI, and another placed outside measuringRSSI, in approximately the same location (e.g., inside and outside ofthe B-pillar or door handle), wherein each said sensor 310 acts andreports as two sensors 310 (one inside and one outside). Alternatively,additional antennas 312/sensors 310 may be used, or the antennaplacement may be modified (as shown in the illustrated embodiment ofFIG. 61).

As described above, antenna placement may be modified in an alternateembodiment, for example to increase the number of spatially-correlatedRSSI differentials that may be performed within the system 100, as shownin the illustrated embodiment of FIG. 61. In this system 100, forexample, differentials may be computed between RSSI measurements ofantennas 312-1 and 312-9, 312-7 and 312-12, 312-8 and 312-12, 312-6 and312-11, and so on.

E.3.x Twelve (12) Antenna AoA RSSI System (12 Combined)

The above thirteen (13) antenna AoA-RSSI system embodiment, without thecenter combined antenna (antenna 312-23).

E.3.y Fifteen (15) Antenna AoA RSSI System (15 Combined)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 62, the system 100 may use angle of arrival (AoA) andRSSI with fifteen (15) combined antennas 312. In this system 100, theantenna placements for an eight (8) antenna system, which is a variationof the twelve (12) antenna AoA system (as described in Section E.2.a,antennas 312-1 through 312-8) without inside antennas 312, and for aseven (7) antenna system (antennas 312-9 through 312-12, 312-15, 312-16,312-19), which is a variation of the eleven (11) antenna RSSI system (asdescribed in E.1.c) without rear driver side and rear passenger sideantenna pairs (i.e., equivalent to the seven [7] antenna RSSI systemdescribed in E.1.b), are combined, but each antenna 312 is a combinedantenna 312 (e.g., sensor 310) capable of reporting both angle and RSSI(either together or separately). As previously described, said combinedantennas 312 (sensors 310) may comprise of one or more antennas 312 (orantenna arrays), and may or may not be physically combined/collocated.As previously described, said combined antennas 312 may provide one ormore angle measurements (e.g., horizontal, vertical, or horizontal andvertical angle measurements, etc.).

In this system 100, antennas 312-9 through 312-12 may use the previouslydescribed placements, or alternately, they may be moved more towards thecenter of the sides of the vehicle 500, such as on or near the B-pillaror door handle.

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this fifteen (15) antenna AoA-RSSIsystem, it is assumed that the set of potential zones 400 is the sameset as described within the previously disclosed twenty-three (23)antenna AoA-RSSI system; however, as also previously disclosed, thesystem 100 may use additional and/or fewer zones 400, with the same ordifferent boundaries/definitions.

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 61. A possible advantage of this antenna 312placement configuration over the previously described thirteen (13)combined antenna system 100, is that each side has an additionalcentered combined antenna 312 that may be used to provide zonedetermination assistance and/or additional zone bounding.

E.3.z Eleven (11) Antenna AoA RSSI System (11 Combined, Center)

The above fifteen (15) antenna AoA-RSSI system embodiment, without thefront-facing front and rear-facing rear combined antennas (antennas312-2, 312-3, 312-6, 312-7), as shown in the illustrated embodiment ofFIG. 63.

E.3.aa Eleven (11) Antenna AoA RSSI System (11 Combined)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 64, the system 100 may use angle of arrival (AoA) andRSSI with eleven (11) combined antennas 312. In this system 100, theantenna placements for the eleven (11) antenna RSSI system (as describedin E.1.c) is used, but each antenna 312 is a combined antenna 312 (e.g.,sensor 310) capable of reporting both angle and RSSI (either together orseparately). As previously described, said combined antennas 312(sensors 310) may comprise one or more antennas 312 (or antenna arrays),and may or may not be physically combined/collocated. As previouslydescribed, said combined antennas 312 may provide one or more anglemeasurements (e.g., horizontal, vertical, or horizontal and verticalangle measurements, etc.).

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this eleven (11) antenna AoA-RSSI system,it is assumed that the set of potential zones 400 is the same set asdescribed within the previously disclosed twenty-three (23) antennaAoA-RSSI system; however, as also previously disclosed, the system 100may use additional and/or fewer zones 400, with the same or differentboundaries/definitions.

The described set of potential zones 400, along with the field of view412 of each AoA antenna, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are depicted in theillustrated embodiment of FIG. 64.

E.3.bb Ten (10) Antenna AoA RSSI System (10 Combined)

The above eleven (11) antenna AoA-RSSI system embodiment, without thecenter combined antenna (antenna 312-23).

E.3.cc Seven (7) Antenna AoA RSSI System (7 Combined)

In one embodiment of a vehicle microlocation system 100, shown forexample in FIG. 65, the system 100 may use angle of arrival (AoA) andRSSI with seven (7) combined antennas. In this system 100, the antennaplacements for the seven (7) antenna RSSI system (as described in E.1.b)is used, but each antenna 312 is a combined antenna 312 (e.g., sensor310) capable of reporting both angle and RSSI (either together orseparately). As previously described, said combined antennas 312(sensors 310) may comprise one or more antennas 312 (or antenna arrays),and may or may not be physically combined/collocated. As previouslydescribed, said combined antennas 312 may provide one or more anglemeasurements (e.g., horizontal, vertical, or horizontal and verticalangle measurements, etc.).

The methods used to determine the position of, and/or distance to, aportable device 110 in this system 100 are similar to those used in thetwenty-three (23) antenna AoA-RSSI system previously described.

For the purposes of disclosing this seven (7) antenna AoA-RSSI system,it is assumed that the set of potential zones 400 is the same set asdescribed within the previously disclosed twenty-three (23) antennaAoA-RSSI system; however, as also previously disclosed, the system 100may use additional and/or fewer zones 400, with the same or differentboundaries/definitions.

The described set of potential zones 400, along with the field of view412 of each AoA antenna 312, and example thresholds that may be used todefine zones 400 for both AoA and RSSI antennas 312 (withmeasurement/approximation error markers), are shown in the illustratedembodiment of FIG. 65.

E.3.dd Six (6) Antenna AoA-RSSI System (6 Combined)

The above six (6) antenna AoA-RSSI system embodiment, without the centercombined antenna 312 (antenna 312-23).

E.3.ee Other Systems

The above sections describe a number of AoA-RSSI system embodiments, butthere are many alternate configurations that are not described above(with fewer or additional antennas 312, using any combination ofpositioning approaches described herein). For example, usingtime-of-flight-/time-of-arrival-(TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based distance measurement (describedherein) may allow systems with fewer antennas 312, if using the sameradios as existing antennas 312 (or alternately, more antennas 312, ifnew radios are utilized). For example, a configuration using a mixtureof RSSI-only, angle-only, and combined (both RSSI and angle) sensors310/antennas 312 is not explicitly described; however, it is clear fromthe set of embodiments that are described, that said embodiments mayexist, and what methods may be used to assemble and place said sensors310/antennas 312, compute portable device 110 position and/or distance,define and determine zones 400, combine methods, mitigatevulnerabilities, and so on.

In the case of each embodiment, the system 100 may, alternately oradditionally, determine the zone 400 in which the portable device 110 islocated using a trilateration-, multilateration-, multiangulation-, ormultiangulateration-based approach, or any combination thereof(described herein).

In the case of each embodiment, the system 100 may, alternately oradditionally, determine distance using atime-of-flight-/time-of-arrival- (TOF/TOA) and/ortime-difference-of-arrival (TDOA)-based approach (described herein).

E.3.ff Triangulation (Multiangulation), Trilateration, Multilateration,and Triangulateration (Multiangulateration)

The above AoA-RSSI systems are described in terms of combining themethods disclosed for RSSI-only and angle-only systems. It is assumedthat only RSSI measurements (or distance measurements [computed fromRSSI measurements]) are available to determine position in RSSI-onlysystems. It is assumed that only angle measurements are available todetermine position in angle-only systems. In AoA-RSSI systems, bothmeasurements may be available. With angle measurements available frommany antennas 312/sensors 310, multiangulation (including triangulation)may be performed. With both measurements available from many antennas312/sensors 310, multiangulateration (including triangulateration) maybe performed.

It is noted that this section focuses upon trilateration,multilateration, multiangulation, and multiangulateration positioningmethods and their supporting methods, and thus, the methods aredescribed relative to these positioning methods; however, said methodsmay be used with any of the previously described RSSI, AoA, and AoA-RSSImethods.

Multiangulation, or simply angulation, may use two or more angles, witheach angle associated with a known reference position, to compute anunknown position (in this case, of a portable device 110) in a referencecoordinate system (described herein). The reference coordinate system issimply a means to define the position each antenna 312/sensor 310, thecomputed position of the portable device 110, and various zones 400 orattributes of the vehicle 500 (as described herein). Because each angleis associated with a particular antenna 312/sensor 310 position, theinputs (angulation inputs) to a multiangulation algorithm may also beexpressed as <angle, position> pairs. It is noted, that as describedherein, <angle> may be an angle relative to a horizontal axis, avertical axis, or any other axis, or in-fact, multiple anglemeasurements (e.g., <angle_(H), angle_(V)> from both horizontal andvertical axes). Triangulation is multiangulation that involves three (3)positions: a third position is computed using two <angle, position>pairs. As such, all references to triangulation, angulation, and/ormultiangulation in this disclosure may refer to any or all oftriangulation, angulation, or multiangulation. For example, unlessspecified otherwise, all references to triangulation may actually referto triangulation and/or multiangulation/angulation.

Trilateration, despite its name, may use two or more distances (e.g.,three or more), with each distance associated with a known referenceposition, to compute an unknown position (in this case, of a portabledevice 110) in a reference coordinate system (described herein). Becauseeach distance is associated with a particular antenna 312/sensor 310position, the inputs (trilateration inputs) to a trilateration algorithmmay also be expressed as <distance, position> pairs. Trilateration isdifferent from multilateration, and thus, it is noted that trilaterationis not multilateration with three positions.

Multilateration, or MLAT, may use two or more (e.g., three or more)distance deltas (the difference in computed distance), with each deltadistance associated with two known reference positions, to compute anunknown position (in this case, of a portable device 110) in a referencecoordinate system (described herein). Because each distance delta isassociated with two particular antenna 312/sensor 310 positions, theinputs (multilateration inputs) to a multilateration algorithm may alsobe expressed as <distance delta, position₁, position₂> pairs. Althoughmultilateration may be used with a time difference of arrival(TDOA)-based delta distance measuring approach, other delta distancemeasuring approaches, such as the sniffing approach described herein,may be used. Multilateration is different from trilateration, and thus,it is noted that multilateration is not the generalization oftrilateration.

Multiangulateration, or simply angulateration, is the combination ofmultiangulation and trilateration methods, which uses any number of<angle, distance> pairs, with each pair associated with a knownreference position, to compute an unknown position (in this case, of aportable device 110) in a reference coordinate system (describedherein). Multiangulateration approaches using multilateration (insteadof trilateration) may also be used, but such an approach is notexplicitly described herein. Because each <angle, distance> pair isassociated with a particular antenna 312/sensor 310 position, the inputsto a multiangulateration algorithm may also be expressed as <angle,distance, position> triplets. It is noted, that as described herein,<angle> may be an angle relative to a horizontal axis, a vertical axis,or any other axis, or in-fact, multiple angle measurements (e.g.,<angle_(H), angle_(V)> from both horizontal and vertical axes).Triangulateration is multiangulateration that combines triangulation andtrilateration: a third position is computed using two <angle, distance,position> triplets. As such, all references to triangulateration,angulateration, and/or multiangulateration in this disclosure may referto any or all of triangulateration, angulateration, ormultiangulateration. For example, unless specified otherwise, allreferences to triangulateration may actually refer to triangulaterationand/or multiangulateration/angulateration.

RSSI-only-based systems may use trilateration and/or multilateration.Angle-only-based systems may use multiangulation. AoA-RSSI systems mayuse multiangulation, multiangulateration, trilateration,multilateration, or any combination thereof.

It is noted that distance may be computed from RSSI or angle (viamultiangulation); therefore, wherever distance is used, RSSI or angle(or any other unit/derivation of RSSI or angle) may be substitutedand/or added; likewise, wherever RSSI or angle (or any otherunit/derivation of RSSI or angle) is used, distance may be substitutedand/or added. There exist methods where distance is determined withoutrelying upon RSSI or angle, such as via time-of-flight (TOF) andtime-difference-of-arrival (TDOA); the usage of RSSI, angle, and/ordistance in this disclosure is not intended to limit or prevent theusage of TOF, TDOA, or alternate methods, and as such, whereverdistance, RSSI, and/or angle is used in reference to distancemeasurement/evaluation, distance may refer to distance computed by suchalternate methods, and RSSI or angle may be substituted with the sourcemeasurement (e.g., time, delta time, etc.).

As described herein, in an AoA-RSSI system, related (correlated) angleand distance measurements (e.g., angle and RSSI measurements from thesame position) may be referred to as <angle, distance> pairs, which maybe provided, as described above, via one sensor 310 using one or moreantennas 312 (e.g., from a sensor 310 with one antenna array thatprovides both angle and distance, from a sensor 310 with an antennaarray that provides angle and another antenna 312 that providesdistance, from a sensor 310 with multiple antenna arrays that providesmultiple <angle, distance> pairs, etc.), via multiple sensors 310 usingone or more antennas 312 (e.g., one sensor 310 may provide angle andanother nearby sensor 310 may provide distance, etc.), or anycombination thereof. It is noted, that as described herein, <angle> maybe an angle relative to a horizontal axis, a vertical axis, or any otheraxis, or in-fact, multiple angle measurements (e.g., <angle_(H),angle_(V)> from both horizontal and vertical axes). Any given sensor 310may report multiple <angle, distance> pairs (e.g., one sensor 310 may beconnected to multiple antennas 312, with each antenna 312 located withdifferent fields of view and/or in different positions on the equipment[e.g., inside and outside], etc.). In an AoA-RSSI system using thesniffing approach described herein, <angle, distance> pairs may beobtained from the same signal transmission across many antennas 312 andthus may be additionally temporally-, frequency-, andspatially-correlated. Some positioning algorithms may benefit from such<angle, distance> pairs, such as multiangulateration-based algorithms.The <distance> component may include a distance relative to the portabledevice 110 (absolute or delta), a distance relative to one or more otherantennas 312/sensors 310 (e.g., delta distances, similar to adelta-based multilateration approach), or any combination thereof.Similarly, the <angle> component may include one or more angles relativeto the portable device 110 (absolute or delta), one or more anglesrelative to one or more other antennas 312/sensors 310 (e.g., deltaangles, similar to a delta-based multilateration approach), or anycombination thereof. In the provided example embodiments, antenna312/sensor 310 position (and corresponding position information) isfixed (static); however, alternate embodiments exist whereantenna/sensor position may be partially dynamic (i.e., may move fromone position to some number of other positions based upon equipmentstate [e.g., an antenna 312/sensor 310 on a door 142, etc.]) or fullydynamic (i.e., corresponding position information is determined inreal-time [e.g., by alternate systems/methods, by using other fixedantennas 312/sensors 310, etc.]).

The previously described embodiments determine the position of aportable device 110 relative to defined zones 400 in and around avehicle 500. A trilateration-, multilateration-, multiangulation-, ormultiangulateration-based method may also determine the position of aportable device 110 relative to zones 400 defined in and around avehicle 500, and thus, may be combined with, or used instead of, anypreviously described methods (e.g., by using the trilateration,multilateration, multiangulation, and/or multiangulateration results asan additional input into the agreement algorithm (i.e., combinationmethod[s]) amongst each positioning method [e.g., RSSI-based,angle-based, AoA-RSSI, etc.], by using only trilateration,multilateration, multiangulation, and/or multiangulateration [requiringno combination method], etc.). Alternatively, or additionally, anAoA-RSSI system using trilateration, multilateration, multiangulation,and/or multiangulateration, may report the determined portable device110 position relative to the vehicle 500 in its reference coordinatesystem (described herein). Alternatively, or additionally, an AoA-RSSIsystem using trilateration, multilateration, multiangulation, and/ormultiangulateration may report the distance to the vehicle 500 from thedetermined portable device 110 position.

There exist embodiments using any combination of multiangulation,multiangulateration, multilateration, and trilateration methods,including embodiments that use previously disclosed RSSI, AoA, andcombined AoA-RSSI methods to determine the position of a portable device110. For example, an embodiment of an AoA-RSSI system that additionallyuses multiangulation to determine the zone 400 in which a portabledevice 110 is located and/or compute its relative distance.

Similar to other embodiments, the portable device 110 communicates witha master device 120 located on the interior of the vehicle 500 that isseparate from the antennas 312/sensors 310 that measure angle andRSSI/distance.

In trilateration-, multilateration-, multiangulation, andmultiangulateration-based methods, positions are expressed using thesystem's reference coordinate system (e.g., a 2D Cartesian [x, y]coordinate system with [0, 0] defined at the center of the vehicle 500,a 3D Cartesian [x, y, z] coordinate system with [0, 0, 0] defined at thecenter of the vehicle 500, a 2D polar [angle, distance] coordinatesystem with [0°, 0] defined at the center of the vehicle 500, a 3D polarcoordinate system, etc.). The position of each trilateration,multilateration, angulation, and/or angulateration input (e.g., antenna312/sensor 310, as described above), as well as the computed position ofthe portable device 110, is expressed relative to the referencecoordinate system (e.g., sensor 1 is located at [−4, −4], sensor 2 islocated at [4, 4], sensor 3 is located at [0, 0], and so on). Positionunits used within the reference coordinate system may be arbitrary andmay have any desired precision (or lack of precision): the unit may bemeters with floating-point values that reflect actual position relativeto the center of the vehicle 500 (e.g., sensor 1 is located at [−1.1 m,1.4 m], which may simplify implementation, if the goal is to determineand report a position in the reference coordinate system and/ordistance), the unit may be undefined with integer values that reflectrelative position relative to the center of the vehicle 500 (e.g.,sensor 1 is located at [−4, 4], requiring a conversion to a real unit ofmeasure, if such an operation is considered necessary), or a combinationof both (comprising units that reflect actual position and undefinedarbitrary values), such as a 3D Cartesian system where x and y aredefined in meters, and z in terms of high, center, and low (e.g., [−1.1m, 1.4 m, center]).

In trilateration-, multilateration-, multiangulation, andmultiangulateration-based methods, where portable device 110 position isreported in terms of presence within a particular zone 400, theboundaries of each zone 400 are defined relative to the system'sreference coordinate system. The system may determine zero or more zones400 in which the portable device 110 may be located by using thedetermined portable device 110 position and the defined zone boundariesto report the one or more applicable zones 400. Zone boundaries may bedefined by any means (e.g., bounding coordinates, center coordinate plusradius, anchor coordinates plus formulas, list of coordinates and/orcoordinate ranges, etc.) to represent any shape (e.g., rectangular,circular, triangular, parallelogram, pentagon, etc.).

An example 2D Cartesian reference coordinate system is shown in theillustrated embodiment of FIG. 66; in addition to a depiction of thereference coordinate system itself, the figure includes two examplecomputed portable device 110 positions (determined using triangulationand multiangulation with five [5] angulation inputs) and several examplerectangular zones 400.

The depicted example zones 400 are similar to those in the otherdisclosed systems: A) inside, B) outside near driver side, C) outsidenear passenger side, D) outside near tailgate/trunk, E) outside nearfront, F) not near the vehicle 500, but within one or more secondarythresholds, G) not near the vehicle 500, but connected, and H) notconnected (not shown).

Similar to other disclosed systems, additional (or fewer) zones 400 maybe defined, with varying levels of accuracy. For example, inside zones400 may be added, another outside zone 400 may be defined outside of thenear zones 400, that extends further away from the vehicle 500, zone Fmay not exist, or additional near zones 400 at various positions may bedefined. Vertical zones 400 may also be defined, also with varyinglevels of accuracy. For example, low, medium, and high vertical zones400 may be defined for near zones 400. The ability of the system 100 toaccurately determine whether or not the device is located within whatzone 400 may be limited by the underlying capabilities of thecommunications medium (e.g., BLE vs. UWB vs. LF) and accuracy of RSSIand angle measurement facilities (e.g., measurement/approximationerror).

The system 100 may determine the position of a portable device 110relative to a reference coordinate system by combining a set of zero ormore portable device 110 positions computed using trilateration,multilateration, multiangulation, multiangulateration algorithms (i.e.,using three or more angulation inputs), or any combination thereof. Forexample, the system 100 may compute a position of the portable device110 using triangulation using just one pair of angulation inputs, asshown in the following figure using antennas 312-1 and 312-2. Forexample, the system 100 may produce many computed positions of theportable device 110 using triangulation across the many pairs in a setof angulation inputs, as shown in the following figure using antennas312-4 through 312-8. For example, the system 100 may compute a positionof the portable device 110 using a 5-input multiangulation algorithm, asshown in the following figure using antennas 312-4 through 312-8.

The set of trilateration, multilateration, angulation, and/orangulateration inputs used to compute a position may vary for the samereasons, and in the same ways, that the sets of antennas 312 in RSSI-and angle-based methods may vary. In one embodiment usingmultiangulation, the system 100 always includes all angulation inputs inthe set from which to compute portable device 110 positions. In analternate embodiment using multiangulation, for example, if the portabledevice 110 is determined to be in zone A using other methods, the system100 may use only inside angulation inputs to compute portable device 110positions. In an alternate embodiment, for example, if the portabledevice 110 is determined to be in zone B using other methods, the system100 may use only driver side angulation inputs to compute portabledevice 110 positions.

The combination of inputs from within a set of trilateration,multilateration, angulation, and/or angulateration inputs may vary forthe same reasons, and in the same ways, that the sets of differentialsand thresholds in RSSI- and angle-based methods may vary. For example,angulation inputs may be absent, not satisfy a threshold (e.g., tooweak), or be unsteady/inconsistent, in which case, said angulationinputs may be ignored within or removed from the angulation input set.In one embodiment using triangulation, the system 100 always computes aportable device 110 position for each unique angulation input pair inthe angulation input set. In an alternate embodiment usingmultiangulation, for example, specific combinations of angulation inputsmay be used to compute a portable device 110 position in differentangulation input sets.

In an embodiment where multiple methods (trilateration, multilateration,angulation, and/or angulateration) are used to compute position, onemethod may be adjusted based upon the set of inputs or outputs fromanother method, or one method may be given priority over another methodbased upon the set of inputs or outputs (e.g., if certain inputs are notavailable/valid, trilateration may be used instead of triangulation,etc.).

The set of computed portable device 110 positions may be combined toyield a single (combined) computed portable device 110 position bycomputing the centroid of the set, determining a median position withinthe set, clustering (e.g., k-means, by threshold, etc.) positions withinthe set and selecting the cluster with the most positions, requiring allpositions to be the same or near one another (i.e., within one or morethresholds of one another), any other method, or any combinationthereof. If the input set was empty (i.e., there are no computedportable device 110 positions), or the computed positions vary too much,the system 100 may report the combined computed portable device 110position as unknown.

In an embodiment where multiple methods (trilateration, multilateration,angulation, and/or angulateration) are used to compute position, acombined computed portable device 110 position may exist for eachmethod. Each said combined computed portable device 110 position may bereported or used in subsequent processing, or alternately, or inaddition, they may be combined, using any of the aforementioned methodsto yield a single combined computed portable device 110 position thatencapsulates multiple positioning methods.

In one embodiment, using the combined computed portable device 110position, the zone 400 in which the portable device 110 is located maybe selected using the defined zone boundaries (e.g., no overlapping zoneboundaries). In an alternate embodiment, the portable device 110position may be mapped to more than one zone 400 (e.g., overlapping zoneboundaries), in which case, amongst the set of possible zones 400, themost probable possible zone 400 (e.g., zone 400 that is most consistentwith the last known portable device 110 position, etc.) may be selectedas the determined zone 400 (or, alternatively, all possible zones 400reported).

Alternately, or in addition, a set of possible zones 400 in which theportable device 110 is located may be formed that includes of all zones400 in which the portable device 110 may be located using the definedzone boundaries across all computed portable device 110 positions; fromthe resultant set of possible zones 400, the most probable possible zone400 (e.g., zone 400 with the most duplicates in the set, zone 400 thatis most consistent with the last known portable device 110 position, anyother method, or any combination thereof) may be selected as thedetermined zone 400 (or, alternatively, all unique possible zonesreported). This approach is the same whether or not overlapping zoneboundaries may be present.

The system 100 may use both approaches (described above, i.e.,combining-then-determining [using the combined computed portable device110 position] vs. determining-then-combining [using the set of computedportable device 110 positions [not combined]]) to generate sets ofpossible zones 400 simultaneously or at different times. If bothapproaches are used simultaneously, requiring agreement between saidzone determination approaches may provide additional protection againstan incorrect zone determination (such as when the computed portabledevice 110 positions vary significantly). The sets of possible zones 400generated by each approach may be combined into a single set of possiblezones 400 prior to subsequent processing steps (using any combinationmethod, some of which are described below), or they may not be combined,simply resulting in additional sets of possible zones 400 to beprocessed in subsequent steps.

In an embodiment where multiple methods (trilateration, multilateration,angulation, and/or angulateration) are used to compute position, a setof possible zones 400 (which may just be the determined zone 400) mayexist for each method. Each said set of possible zones 400 may bereported or used in subsequent processing, or alternately, or inaddition, they may be combined to yield a single combined set ofpossible zones 400 (which may be just the determined zone 400) thatencapsulates multiple positioning methods. The sets of possible zones400 may be combined by simply concatenating each method's set ofpossible zones 400 and then removing duplicate entries, by building aset of possible zones 400 that includes only zones 400 that are presentin each set of possible zones 400 (or that are present in one or moreother sets of possible zones 400), by building a set of possible zones400 that only include zones 400 that are adjacent to one another, bybuilding a set of possible zones 400 that are probable or possible giventhe current position of the portable device 110, or any other method, orany combination thereof.

In one embodiment, a single determined zone 400 may be reported as aresult of the trilateration, multilateration, angulation, and/orangulateration process. If the combined computed portable device 110position is unknown, or there were no computed portable device 110positions (i.e., there are no non-empty sets of possible zones 400), thesystem 100 may select an appropriate zone 400 (e.g., zone G), reportthat it was unable to determine a zone 400, or any combination thereof.If two or more unique possible zones 400 remain after the aforementionedprocessing, the system 100 may select one of them to report as thedetermined zone 400 using any of the disclosed zone selection methods,select an appropriate zone 400 (e.g., zone G, the zone 400 thatencompasses all possible zones 400, etc.), report that it was unable todetermine a zone 400, or any combination thereof. In an alternateembodiment, more than one determined zone 400 may be reported, in whichcase, the system 100 may report all possible zones 400 or a subset ofthe possible zones 400 (e.g., the system 100 may perform any of theabove described filtering on the set of possible zones 400 prior toreporting).

In embodiments where multiple methods (trilateration, multilateration,angulation, and/or angulateration) are used to compute position, theresults of each positioning method may be reported individually (asdescribed above). In an alternate embodiment, the results of alltrilateration, multilateration, angulation, and/or angulaterationmethods may be combined and/or reported using any of the methodsdescribed above.

In one embodiment, the system 100 may provide, for each reported zone400, a correctness likelihood indicator (e.g., a confidencescore/metric, a likelihood score/metric, probability relative to otherreported zones 400 and/or the current zone 400, etc.).

The system 100 may report the distance to the combined computed portabledevice 110 position from the center of the vehicle 500 (and/or one ormore other reference positions, such from the skin of the driver,passenger, and/or rear cabin). In embodiments where multiple methods(trilateration, multilateration, angulation, and/or angulateration) areused to compute position, such distances may be reported for eachmethod. In an alternate embodiment, the computed distances of alltrilateration, multilateration, angulation, and/or angulaterationmethods may be combined using any of the above described methods (e.g.,averaging, median, minimum, maximum, clustering, etc.).

Positioning results (within one method or amongst multiple methods) maybe combined/filtered using any combination of disclosed methods,including, but not limited to, the subsequently disclosed combinationmethods, Kalman filters, particle filters, probabilisticestimation/filters, fingerprinting, and heuristics.

As described herein, the reported results of trilateration,multilateration, angulation, and/or angulateration methods may beintegrated into the described RSSI, AoA, or AoA-RSSI systems.

E.3.gg TOF (Time-of-Flight) and TDOA (Time-Difference-of-Arrival)

Distance measurement may be considered a useful aspect of RSSI, AoA, andAoA-RSSI systems. Distances may be used in zone 400 determinationprocesses, reported to users or other actors of or within the system100, or used for other purposes in the system 100 (e.g., when to applycertain security restrictions, when to transition from one state orconnection strategy to another, when to transition to/from idle,low-power, long-range, near, or other operating modes, etc.).

The accuracy and precision of distance computed from RSSI is limited bythe underlying capabilities of the communications medium (e.g., BLE vs.UWB vs. LF) and accuracy of RSSI and angle measurement facilities (e.g.,measurement/approximation error).

The accuracy and robustness of the system's distance measurement methodsare as much contributors to system security as they are to userexperience. For example, distance may be used to distinguish betweennear (passive entry) and far (approach) zones 400. The vehicle 500 mayallow the user to passively unlock and/or enter their vehicle 500 whenin a near zone 400, but not when in a far zone 400. Inaccuracies orvulnerabilities in the distance measurement approach may result inundesired user-facing behavior, such as not allowing the vehicle 500 tounlock when the user is actually within a near zone 400, or securityconcerns, such as allowing the vehicle 500 to unlock when the user isactually in a far zone 400. This necessitates the use of secure rangingapproaches, such as distance-bounding, as described herein in thisdisclosure.

As described herein in this disclosure, RSSI and angle measurements maybe vulnerable to reflectors and blockers; in turn, distance computedfrom RSSI or angles may be vulnerable to reflectors and blockers. Somecommunications mediums are not (or are less) vulnerable to reflectionsand attenuations from materials that may exist in the environments inwhich people and vehicles 500 operate (e.g., UWB, LF); however, BLE, forexample, is vulnerable, as it is reflected and attenuated by commonmaterials (e.g., metal, wood, water, concrete, etc.). In vulnerablecommunications mediums, reflectors and blockers may be placedstrategically by malicious actors to increase or decrease the distancecomputed by the system 100 to their possible advantage.

RSSI and angle measurements are also vulnerable to relay attacks, wherean actor receives and re-transmits signals from a portable device 110using another portable device 110 (e.g., allowing the actor to gainaccess to the vehicle 500 without the authorized portable device 110actually being near the vehicle 500).

The distance measurement methods using RSSI and angle measurementsdescribed within this disclosure defend against such vulnerabilities,for example by computing distance using a number of antennas 312 andthen intelligently combining the results, but said methods do notentirely mitigate said vulnerabilities. For example, a person standingbetween the portable device 110 and the system of antennas 312 (e.g.,vehicle 500) may influence the distance measurement significantly(despite our ability to still determine that the portable device 110 isnear the vehicle 500).

Instead of using RSSI and angle measurements to compute distance,distance may be computed using the time-of-flight/time-of-arrival(TOF/TOA) or time-difference-of-arrival (TDOA) of signals from theportable device 110 at various antennas 312. Such approaches may not be,or may be significantly less, vulnerable to reflectors and blockers(since distance is computed based upon propagation time, which variesvery little due to reflectors and blockers). Such approaches, in systemsthat employ adequate (to the communications medium) timing requirements,may also not be, or may be significantly less, vulnerable to relayattacks, since propagation time is precisely measured, and propagationtime may be significantly faster than the time utilized for an attackerto relay the signal to/from the portable device 110. Some systems mayincorporate additional hardware/radios to perform more accurate distancemeasurement (e.g., a combined BLE/UWB system, or a BLE/LF system, etc.).Some systems may incorporate proprietary or custom communicationsprotocols using standard hardware/radios (e.g., a custom [possiblynon-BLE] protocol on BLE hardware, etc.).

RSSI-based, angle-based, and AoA-RSSI systems may perform distancemeasurements using TOF/TOA and/or TDOA, in addition to, or in place of,RSSI- and/or angle-based methods. For example, a BLE-based system thatuses TOF on BLE hardware, RSSI, and angle-based methods. For example, aBLE-and-UWB-based system that uses UWB and/or TOF on BLE hardware, RSSI,and angle-based methods, based upon which is available in the portabledevice 110. For example, a BLE-and-LF-based system that uses LF and/orTOF on BLE hardware, RSSI, and angle-based methods, based upon which isavailable in the portable device 110. For example, aBLE-and-UWB-and-LF-based system that uses UWB, LF, and/or TOF on BLEhardware, RSSI, and angle-based methods, based upon which is availablein the portable device 110.

TOF-/TOA- and/or TDOA-based distance measurements may be used within anyof the positioning methods described within this disclosure. In oneembodiment, such distance measurements may be used as a substitute forRSSI (or any other value related to or derived from RSSI, e.g., byconverting distance to RSSI to avoid, supplement, or replace traditionalRSSI measurement [e.g., if traditional RSSI measurements are unavailableor may not be used]).

DIY/Hobbyist/Prototyping Microlocation System.

In one embodiment, one or more components of the above described system100 may be made available for purchase, without the said componentsbeing allocated to a particular application (other than what thepurchaser decides). The embodiment may allow experimentation, education,evaluation, and prototyping using the pre-packaged system components.Users may purchase system components and assemble them in aconfiguration that meets their needs. The user may then integrate thisconfiguration with other systems.

The present disclosure, according to one embodiment, provides a meansfor people to easily build application-specific microlocation systems.Microlocation systems may be configured to precisely determine thelocation of a device relative to a set of antennas 312/sensors 310(e.g., embedded in a product [e.g., vehicle 500, door lock, ATM, etc.]or as part of a service [e.g., shopping, museum, etc.]).

Conventional location systems may use beacons and try to eitherdetermine to which beacon a device is closest using RSSI, or to attemptto trilaterate using a set of RSSIs measured from different beacons atdifferent times in different locations using different signals (eachsensor 310 having only one antenna 312). These systems are vulnerable toinconsistency introduced by their spatial and temporal differences(e.g., objects moving in the environment that attenuate or reflectsignals, such as the human body or metallic objects). One or moreembodiments according to the present disclosure differ, in that, for agiven sensor 310, we are measuring RSSIs obtained from potentiallymultiple antennas 312 for the same signal at, for all intents andpurposes, the same time, in the same location). When used in conjunctionwith the systems and methods described in U.S. Provisional Appl. No.62/323,262 to Raymond Michael Stitt, filed Apr. 15, 2016, and entitledSYSTEM AND METHOD FOR ESTABLISHING REAL-TIME LOCATION (the disclosure ofwhich is incorporated herein by reference in its entirety), the system100 may obtain these measurements at the same time from all sensors 310for a given device. The spatial and temporal correlation of antennas 312for virtual boundary sensors and measurements in this system 100 maylessen the environmental effects that impact traditional sensors(fast-fading effects, moving objects, constructive/destructiveinterference, etc.) and produces more consistent data sets (allowingsome effects to be isolated and/or turned into fingerprintingadvantages).

Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,”“upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are usedto assist in describing the invention based on the orientation of theembodiments shown in the illustrations. The use of directional termsshould not be interpreted to limit the invention to any specificorientation(s).

The above description is that of current embodiments of the invention.Various alterations and changes can be made without departing from thespirit and broader aspects of the invention as defined in the appendedclaims, which are to be interpreted in accordance with the principles ofpatent law including the doctrine of equivalents. This disclosure ispresented for illustrative purposes and should not be interpreted as anexhaustive description of all embodiments of the invention or to limitthe scope of the claims to the specific elements illustrated ordescribed in connection with these embodiments. For example, and withoutlimitation, any individual element(s) of the described invention may bereplaced by alternative elements that provide substantially similarfunctionality or otherwise provide adequate operation. This includes,for example, presently known alternative elements, such as those thatmight be currently known to one skilled in the art, and alternativeelements that may be developed in the future, such as those that oneskilled in the art might, upon development, recognize as an alternative.Further, the disclosed embodiments include a plurality of features thatare described in concert and that might cooperatively provide acollection of benefits. The present invention is not limited to onlythose embodiments that include all of these features or that provide allof the stated benefits, except to the extent otherwise expressly setforth in the issued claims. Any reference to claim elements in thesingular, for example, using the articles “a,” “an,” “the” or “said,” isnot to be construed as limiting the element to the singular. Anyreference to claim elements as “at least one of X, Y and Z” is meant toinclude any one of X, Y or Z individually, and any combination of X, Yand Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z.

1. A system for establishing location information with respect to aportable device and an object, the system comprising: a master devicedisposed in a fixed position relative to the object, said master devicecapable of communicating with at least one of the portable device andone or more sensor devices; a plurality of antennas, each of saidplurality of antennas configured to receive wireless communications andprovide an antenna output corresponding to the wireless communications,wherein a characteristic signal is determined for at least one antennaoutput based on a plurality of time-spaced measurements of the at leastone antenna output, said at least one antenna output corresponding to atleast one of a plurality of different wireless communication frequenciesat each time of said plurality of time-spaced measurements; and whereinan output signal is determined based on a function of saidcharacteristic signal, wherein a location of the portable device isdetermined relative to the object based on said output signal, wherebysaid function mitigates environmental effects in said at least oneantenna output.
 2. The system of claim 1 wherein said characteristicsignal is determined for each said antenna output of said plurality ofantennas, and wherein said output signal is determined for each saidcharacteristic signal based on the function.
 3. The system of claim 2wherein said characteristic signal for a first antenna output isdetermined with respect to a characteristic that is different from acharacteristic that forms the basis for said characteristic signal for asecond antenna output, and wherein said function applied to saidcharacteristic signal for said first antenna output is different from afunction applied to said characteristic signal for said second antennaoutput.
 4. The system of claim 2 wherein said output signal correspondsto an exponential moving average of the time-spaced measurements of saidcharacteristic signal, and wherein said time-spaced measurements foreach said antenna output for a given time are frequency correlated. 5.The system of claim 2 wherein a combined signal is determined as afunction of at least two of said characteristic signals, wherein saidfunction is applied to temporally and frequency correlated values ofsaid at least two signal characteristics.
 6. The system of claim 5wherein said function is a difference function, wherein said at leasttwo characteristic signals includes a first characteristic signal and asecond characteristic signal, wherein each value of said combined signalcorresponds to a difference between a first value of said firstcharacteristic signal and a second value of said second characteristicsignal, and wherein said first and second values correlate to the sametime and the same frequency of the wireless communications.
 7. Thesystem of claim 2 wherein a combined signal is determined as a functionof at least two output signals, wherein an output analysis function isapplied to temporally correlated values of said at least two outputsignals.
 8. The system of claim 1 wherein said master device isconfigured to determine said output signal and said location of theportable device based on said output signal.
 9. The system of claim 1wherein at least one of said one or more sensor devices is operablycoupled to said plurality of antennas, wherein said at least one sensordevice is configured to determine said output signal, and wherein saidat least one sensor device communicates a signal characteristic of saidoutput signal to said master device.
 10. The system of claim 9 whereinsaid at least one sensor device is configured to determine said outputsignal, and wherein said at least one sensor device communicates asignal characteristic of said output signal to said master device. 11.The system of claim 1 wherein said at least one sensor devicecommunicates said at least one antenna output to said master device viaa communication channel separate from a communication channel used forreception of said wireless communications, wherein said master devicedetermines said characteristic signal and said output signal based onsaid characteristic signal. 12.-19. (canceled)
 20. The system of claim 1wherein said function includes at least one of determining an average, amaximum, a minimum, and clustering with respect to said at least twotime-spaced values of said characteristic signal, wherein said averageis determined as an exponential moving average wherein a weighting ofsaid exponential moving average is based on the number of previous Nvalid measurements.
 21. The system of claim 1 wherein saidcharacteristic signal is determined with respect to time-spacedmeasurements of said at least one antenna output, wherein two or more ofsaid time-spaced measurements are obtained with respect to wirelesscommunications that occur on different communication frequencies. 22.The system of claim 21 wherein said two or more of said time-spacedmeasurements correspond to two or more RSSI measurements with respect towireless communications that occur on said different communicationfrequencies. 23.-33. (canceled)
 34. A system for determining locationinformation with respect to a portable device and an object, the systemcomprising: a master device disposed in a fixed position relative to theobject, said master device capable of communicating with at least one ofthe portable device and one or more sensor devices; a plurality ofantennas, each of said plurality of antennas configured to receivewireless communications, wherein a plurality of signal characteristicsof said wireless communications are detected via antenna signal outputfrom said plurality of antennas; wherein said plurality of antennasincludes first and second antennas arranged to define a first virtualboundary between first and second zones, wherein a position of theportable device relative to said first virtual boundary is determinedbased on a difference between a first signal characteristic determinedfrom antenna signal output from said first antenna and a second signalcharacteristic determined from antenna signal output from said secondantenna; and wherein said plurality of antennas includes third andfourth antennas arranged to define a second virtual boundary betweenthird and fourth zones, wherein a position of the portable devicerelative to the second virtual boundary is determined based on adifference between a third signal characteristic determined from antennasignal output from said third antenna and a fourth signal characteristicdetermined from antenna signal output from said fourth antenna.
 35. Thesystem of claim 34 wherein said second antenna and said fourth antennaare the same antenna and wherein the first and third antennas aredifferent antennas.
 36. The system of claim 34 wherein each of saidplurality of antennas is coupled to a different sensor of said one ormore sensor devices.
 37. The system of claim 34 wherein said fourth zoneand said second zone form a compound zone. 38.-39. (canceled)
 40. Amethod of determining position with respect to a portable device and anobject, said method comprising: receiving in a first antenna wirelesscommunications transmitted from a target device, wherein the wirelesscommunications are transmitted at least one of a plurality ofcommunication frequencies; determining a first characteristic signalbased on the wireless communications received in the first antenna;receiving in a second antenna wireless communications transmitted fromthe target device; determining a second characteristic signal based onthe wireless communications received in the second antenna; generatingat least one output characteristic as a function of the first and secondcharacteristic signals, wherein the first and second characteristicsignals are aligned in time and frequency with respect to the wirelesscommunications; and determining, based on the at least one outputcharacteristic, a position of the target device relative to the firstand second antennas. 41.-45. (canceled)
 45. The method of claim 40wherein said determining the first characteristic signal includesconducting a plurality of first time-spaced measurements with respect tofirst antenna output from the first antenna, wherein at least two of thefirst time-spaced measurements correspond to wireless communicationsthat occur at different communication frequencies; wherein saiddetermining the second characteristic signal includes conducting aplurality of second time-spaced measurements with respect to secondantenna output from the second antenna, wherein the secondcharacteristic signal is aligned in time with the first characteristicsignal, wherein at least two of the second time-spaced measurementscorrespond to the wireless communications that occur at the differentcommunication frequencies such that the at least two time-spacedmeasurements of the second time-spaced measurements correlate infrequency with the at least two time-spaced measurements of the firsttime-spaced measurements; determining a plurality of outputcharacteristics for each of the first and second time-spacedmeasurements, wherein each of the first and second time-spacedmeasurements are correlated in time and provided respectively to thefunction to determine the plurality of output characteristics, whereinthe plurality of output characteristics forms an output characteristicsignal with values spaced in time.